Understanding the chemistry behind the antioxidant activities of butylated hydroxytoluene (BHT): A review

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Highlights

Modification of BHT has a significant multivariate effect on antioxidant efficiency.

BDE is the key to rational design and development of antioxidants.
Antioxidant performance of BHT is mainly depending on 13 very crucial parameters.
MPAO is a promising way to increase antioxidant and pharmacological activities.

Abstract

Hindered phenols find a wide variety of applications across many different industry sectors. Butylated hydroxytoluene (BHT) is a most commonly used antioxidant recognized as safe for use in foods containing fats, pharmaceuticals, petroleum products, rubber and oil industries. In the past two decades, there has been growing interest in finding novel antioxidants to meet the requirements of these industries. To accelerate the antioxidant discovery process, researchers have designed and synthesized a series of BHT derivatives targeting to improve its antioxidant properties to be having a wide range of antioxidant activities markedly enhanced radical scavenging ability and other physical properties. Accordingly, some structure–activity relationships and rational design strategies for antioxidants based on BHT structure have been suggested and applied in practice. We have identified 14 very sensitive parameters, which may play a major role on the antioxidant performance of BHT. In this review, we attempt to summarize the current knowledge on this topic, which is of significance in selecting and designing novel antioxidants using a well-known antioxidant BHT as a building-block molecule. Our strategy involved investigation on understanding the chemistry behind the antioxidant activities of BHT, whether through hydrogen or electron transfer mechanism to enable promising anti-oxidant candidates to be synthesized.

European Journal of Medicinal Chemistry

Volume 101, 28 August 2015, Pages 295–312

Review article

Understanding the chemistry behind the antioxidant activities of butylated hydroxytoluene (BHT): A review

^aNanotechnology & Catalysis Research Centre, (NANOCAT), University of Malaya, Block 3A, Institute of Postgraduate Studies Building, 50603 Kuala Lumpur, Malaysia
^bDepartment of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
^cDivision of Human Biology, Faculty of Medicine, International Medical University, 57000 Kuala Lumpur, Malaysia
^dDrug Design and Development Research Group, Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
http://www.sciencedirect.com/science/article/pii/S022352341530101X

doi:10.1016/j.ejmech.2015.06.026

1st Wageeh Yehye

University of Malaya
2nd Noor Rahman

University of Malaya
3rd Azhar Ariffin

University of Malaya
4th Sharifah Bee Abd Hamid

University of Malaya
5th Abeer Abdulhadi Abdulqader

University of Malaya
6th Farkaad A Kadir

International Medical University (IMU)
7th Marzieh Yaeghoobi

University of Malaya

SEE

https://www.researchgate.net/publication/278050005_ChemInform_Abstract_Understanding_the_Chemistry_Behind_the_Antioxidant_Activities_of_Butylated_Hydroxytoluene_BHT_A_Review/figures

///////////Antioxidant, Butylated hydroxytoluene, Free radical, Reactive oxygen species, Phenol

Kinetics of Rh(II)-Catalyzed α-Diazo-β-ketoester Decomposition and Application to the [3+6+3+6] Synthesis of Macrocycles on a Large Scale and at Low Catalyst Loadings

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Jul 062016

Kinetics of Rh(II)-Catalyzed α-Diazo-β-ketoester Decomposition and Application to the [3+6+3+6] Synthesis of Macrocycles on a Large Scale and at Low Catalyst Loadings

Daniele Poggiali†, Alexandre Homberg†, Timothée Lathion‡, Claude Piguet‡, and Jérôme Lacour^*†

^†Department of Organic Chemistry and ^‡Department of Inorganic and Analytical Chemistry, University of Geneva, 30 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland

ACS Catal., 2016, 6, pp 4877–4881

DOI: 10.1021/acscatal.6b01283

*E-mail: jerome.lacour@unige.ch

http://pubs.acs.org/doi/full/10.1021/acscatal.6b01283

In the context of [3+6+3+6] macrocyclization reactions, precise kinetics of α-diazo-β-ketoester decomposition were measured by in situ infrared (IR) monitoring. Dirhodium complexes of Ikegami–Hashimoto type—and perchlorinated phthalimido derivatives in particular—performed better than classical achiral complexes. Clear correlations were found between speciation among dirhodium species and catalytic activity. With these results, novel cyclohexyl-derived catalysts were developed, affording good yields of macrocycles (up to 78%), at low catalyst loadings (from 0.01 mol % to 0.001 mol %) and on a large scale (from 1 g to 20 g).

///////acceptor-acceptor diazo reagents, dirhodium complexes, in situ IR monitoring, kinetics, low catalyst loading, multigram synthesis, speciation, ylides

Supporting Info

C–H Arylation of Heterocyclic N-Oxides Through in Situ Diazotisation Of Anilines without Added Promoters: A Green And Selective Coupling Process

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Jul 062016

A green and selective method for the generation of biaryl compounds through C–H arylation of heterocyclic N-oxides, in which the addition of ascorbic acid as a promoter is not required for either the generation of an aryldiazonium species or the subsequent arylation, is presented. Reaction conditions were optimized through multivariate data analysis, including orthogonal projections to latent structures (OPLS) and design of experiments (DoE) methodologies, resulting in further sustainability improvements, and were then applied to a range of substrates to establish the scope and limitations of the process. The reaction was studied using in situ infrared spectroscopy and a mechanism is presented that accounts for the available data from this and previous studies. The reaction was also performed on a multigram scale, with calorimetry studies to support further scale-up of this promoter-free transformation.

C–H Arylation of Heterocyclic N-Oxides Through in Situ Diazotisation Of Anilines without Added Promoters: A Green And Selective Coupling Process

Aymeric P. Colleville^†^‡, Richard A. J. Horan^*^†, Sandrine Olazabal^†, and Nicholas C. O. Tomkinson^‡

^† API Chemistry, GlaxoSmithKline Research and Development Ltd., Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K.

^‡ WestCHEM, Department of Pure and Applied Chemistry, Thomas Graham Building, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, U.K.

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00117

http://pubs.acs.org/doi/full/10.1021/acs.oprd.6b00117

2-(4-(Ethoxycarbonyl)phenyl)pyridine N-Oxide

Orange solid (81 mg, 22% yield), mp 119–120 °C.

¹H NMR (DMSO-d₆, 400 MHz): δ 8.39–8.38 (m, 1H), 8.07 (d, 2H, J = 8.6 Hz), 8.00 (d, 2H, J = 8.6 Hz), 7.72–7.67 (m, 1H), 7.45–7.48 (m, 2H), 4.37 (q, 2H, J = 7.1 Hz), 1.36 (t, 3H, J = 7.1 Hz) ppm.

¹³C NMR (DMSO-d₆, 100 MHz): δ 165.3 (C_IV), 146.6 (C_IV), 140.2, 137.2 (C_IV), 130.2 (C_IV), 129.6, 128.7, 127.7, 126.1, 125.5, 60.9, 14.1 ppm.

HRMS (ESI⁺): calculated for C₁₄H₁₄NO₃ [M+H]⁺ 244.0960, found 244.0968.

//////C–H Arylation of Heterocyclic N-Oxides, Situ Diazotisation Of Anilines, Promoters, Green And Selective Coupling Process

Supporting Info

Rifaximin

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Jul 062016

Rifaximin;

Rifaxidin; Rifacol; Xifaxan; Normix; Rifamycin L 105;L 105 (ansamacrolide antibiotic), L 105SV

(2S,16Z,18E,20S,21S,22R,23R,24R,25S,26S,27S,28E)-5,6,21,23,25-pentahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca-[1,11,13]trienimino)benzofuro[4,5-e]pyrido[1,2-á]-benzimidazole-1,15(2H)-dione,25-acetate

CAS 80621-81-4, 4-Deoxy-4-methylpyrido[1,2-1,2]imidazo[5,4-c]rifamycin SV,

4-Deoxy-4′-methylpyrido[1′,2′-1,2]imidazo[5,4-c]rifamycin SV, Rifacol

C₄₃H₅₁N₃O₁₁
Molecular Weight:	785.87854 g/mol

XIFAXAN tablets for oral administration are film-coated and contain 200 mg or 550 mg of rifaximin.

Rifaximin is an orally administered, semi-synthetic, nonsystemic antibiotic derived from rifamycin SV with antibacterial activity. Rifaximin binds to the beta-subunit of bacterial DNA-dependent RNA polymerase, inhibiting bacterial RNA synthesis and bacterial cell growth. As rifaximin is not well absorbed, its antibacterial activity is largely localized to the gastrointestinal tract.

Rifaximin (trade names:RCIFAX, Rifagut, Xifaxan, Zaxine) is a semisynthetic antibiotic based on rifamycin. It has poor oral bioavailability, meaning that very little of the drug will be absorbed into the blood stream when it is taken orally. Rifaximin is used in the treatment of traveler’s diarrhea, irritable bowel syndrome, and hepatic encephalopathy, for which it receivedorphan drug status from the U.S. Food and Drug Administration in 1998.

Rifaximin is a rifamycin that was launched in 1988 by Alfa Wasserman for the treatment of bacterial infection, and was commercialized in 2004 by Salix for the treatment of Clostridium difficile-associated diarrhea. In 2008, the product was launched in Germany for the treatment of travelers’ diarrhea caused by non-invasive enteropathogenic bacteria in adults. In 2015, Xifaxan was approved in the U.S. for the treatment of abdominal pain and diarrhea in adult men and women with irritable bowel syndrome with diarrhea. At the same year, Aska filed an application for approval of the product in Japan for the treatment of hepatic encephalopathy.

Rifaximin is licensed by the U.S. Food and Drug Administration to treat traveler’s diarrhea caused by E. coli.^[1] Clinical trials have shown that rifaximin is highly effective at preventing and treating traveler’s diarrhea among travelers to Mexico, with fewside effects and low risk of developing antibiotic resistance.^[2]^[3]^[4] It is not effective against Campylobacter jejuni, and there is no evidence of efficacy against Shigella or Salmonella species.

Launched – 1988	Alfa Wassermann	Infection, bacterial
Launched – 2004	Salix	Traveler’s diarrhea
Launched – 2010	Salix	Encephalopathy, hepatic
Launched – 2015	Salix	Irritable bowel syndrome (Diarrhea predominant)
Launched	Alfa Wassermann Merck & Co.	Hyperammonemia

The drug is also at Salix in phase II trials for the treatment of Crohn’s disease. Alfa Wasserman is also conducting phase II trials for Crohn’s disease. The product was approved and launched in the U.S. for the maintenance of remission of hepatic encephalopathy in 2010. Mayo Clinic is conducting phase II clinical trials in the U.S. for the treatment of primary sclerosing cholangitis and the University of Hong Kong is also conducting Phase II trials for the treatment of functional dyspepsia.

It may be efficacious in relieving chronic functional symptoms of bloating and flatulence that are common in irritable bowel syndrome (IBS),^[5]^[6] especially IBS-D.

In February 1998, Salix was granted orphan drug designation by the FDA for the use of rifaximin to treat hepatic encephalopathy. In 2009, a codevelopment agreement was established between Lupin and Salix in the U.S. for the development of a new formulation using Lupin’s bioadhesive drug delivery technology.

There was recentlya pilot-study done on the efficacy of rifaximin as a means of treatment for rosacea, according to the study, induced by the co-presence of small intestinal bacterial overgrowth.^[7]

In the United States, rifaximin has orphan drug status for the treatment of hepatic encephalopathy.^[8] Although high-quality evidence is still lacking, rifaximin appears to be as effective as or more effective than other available treatments for hepatic encephalopathy (such as lactulose), is better tolerated, and may work faster.^[9] Hepatic encephalopathy is a debilitating condition for those with liver disease. Rifaximin is an oral medication taken twice daily that helps patients to avoid reoccurring hepatic encephalopathy. It has minimal side effects, prevents reoccurring encephalopathy and high patient satisfaction. Patients are more compliant and satisfied to take this medication than any other due to minimal side effects, prolong remission, and overall cost.^[10] Rifaximin helps patients avoid multiple readmissions from hospitals along with less time missed from work as well. Rifaximin should be considered a standard prescribed medication for those whom have episodes of hepatic encephalopathy.

The drawbacks to rifaximin are increased cost and lack of robust clinical trials for HE without combination lactulose therapy.

Also treats hyperammonemia by eradicating ammoniagenic bacteria.

Mechanism of action

Rifaximin interferes with transcription by binding to the β-subunit of bacterial RNA polymerase.^[11] This results in the blockage of the translocation step that normally follows the formation of the first phosphodiester bond, which occurs in the transcription process.^[12]

Efficacy

A 2011 study in patients with IBS (sans constipation) indicated 11% showed benefits over a placebo.^[13] The study was supported by Salix Pharmaceuticals, the patent holder.^[13] A 2010 study in patients treated for Hepatic Cirrhosis with hospitalization involving Hepatic encephalopathy resulted in 22% of the rifaxmin treated group experiencing a breakthrough episode of Hepatic encephalopathy as compared to 46% of the placebo group. The majority patients were also receivingLactulose therapy for prevention of hepatic encephalopathy in addition to Rifaximin.^[14] Rifaximin shows promising results, causing remission in up to 59% of people with Crohn’s disease and up to 76% of people with Ulcerative Colitis.^[15]

Availability

In the United States, Salix Pharmaceuticals holds a US Patent for rifaximin and markets the drug under the name Xifaxan, available in tablets of 200 mg and 550 mg.^[16]^[17] In addition to receiving FDA approval for traveler’s diarrhea and (marketing approved for)^[17] hepatic encephalopathy, Xifaxan received FDA approval for IBS in May 2015.^[18] No generic formulation is available in the US and none has appeared due to the fact that the FDA approval process was ongoing. If Xifaxan receives full FDA approval for hepatic encephalopathy it is likely that Salix will maintain marketing exclusivity and be protected from generic formulations until March 24, 2017.^[17] Price quotes received on February 21, 2013 for Xifaxan 550 mg in the Denver Metro area were between $23.57 and $26.72 per tablet. A price quote received on June 24, 2016 for Xifaxan 550 mg was $31.37 per tablet.

Rifaximin is approved in 33 countries for GI disorders.^[19]^[20] On August 13, 2013, Health Canada issued a Notice of Compliance to Salix Pharmaceuticals Inc. for the drug product Zaxine.^[21] In India it is available under the brand names Ciboz and Xifapill.^[

SPECTRA

LINK IS CLICK

APT 13C NMR RIFAXIMIN

1H NMR PARTIAL

Direct infusion mass analysis ESI (+)

IH NMR

[-]ESI FRAG PATHWAY

Synthesis

Rifaximin is a broad-spectrum antibiotic belonging to the family of Rifamycins and shows its antibacterial activity, in the gastrointestinal tract against localized bacteria that cause infectious diarrhoea, irritable bowel syndrome, small intestinal bacterial overgrowth, Crohn’s disease, and/or pancreatic insufficiency.

Rifaximin is sold under the brand name Xifaxan® in US for the treatment of Travellers’ diarrhoea and Hepatic Encephalopathy. The chemical name of Rifaximin is (2S , 16Z, 18E,20S ,21 S ,22R,23R,24R,25S ,26S ,27S ,28E)-5,6,21 ,23 ,25-pentahydroxy-27-methoxy-2,4,1 l,16,20,22,24,26-octamethyl-2,7(epoxypentadeca-[l,l l,13]trienimino) benzofuro[4,5-e]pyrido[l,2-a]-benzimidazole-l,15(2H)-dione,25-acetate and the molecular formula is G^HsiNsOn with a molecular weight of 785.9. The structural formula of Rifaximin is:

Formula I

Rifaximin was first described and claimed in Italian patent IT 1154655 and U.S. Pat. No.4,341,785. These patents disclose a process for the preparation of Rifaximin and a method for the crystallisation thereof. The process for the preparation of Rifaximin is as depicted in scheme I given below:

Scheme -I

U.S. Pat. No. 4,179,438 discloses a process for the preparation of 3-bromorifamycin S which comprises reaction of rifamycin S with at least two equivalents of bromine, per one mole of rifamycin S in the presence of at least one mole of pyridine per each equivalent of bromine and in the presence of ethanol, methanol or mixtures thereof with water at a

temperature not above the room temperature. The process is shown in the scheme given below:

Rifamycin S 3-Bromo-Rifamycin-S

U.S. Patent No.4,557, 866 discloses a process for one step synthesis of Rifaximin from Rifamycin O, which is shown in scheme II given below:

Rifamycin O Rifaximin

Scheme -II

US ‘866 patent also discloses purification of Rifaximin by performing crystallization of crude Rifaximin from a 7:3 mixture of ethyl alcohol/water followed by drying both under atmospheric pressure and under vacuum. The crystalline form which is obtained has not been characterized.

U.S. Patent No. 7,045,620 describes three polymorphic forms α, β and γ of Rifaximin. Form a and β show pure crystalline characteristics while the γ form is poorly crystalline. These polymorphic forms are differentiated on the basis of water content and PXRD. This patent also discloses processes for preparation of these polymorphs which involve use of specific reaction conditions during crystallization like dissolving Rifaximin in ethyl alcohol at 45-65°C, precipitation by adding water to form a suspension, filtering suspension and washing the resulted solid with demineralized water, followed by drying at room temperature under vacuum for a period of time between 2 and 72 hours. Crystalline forms a and β are obtained by immediate filtration of suspension when temperature of reaction mixture is brought to 0°C and poorly crystalline form γ is obtained when the reaction mixture is stirred for 5-6 hours at 0°C and then filtered the suspension. In addition to above these forms are also characterized by specific water content. For a form water content should be lower than 4.5%, for β form it should be higher than 4.5% and to obtain γ form, water content should be below 2%.

U.S. Patent No. 7,709,634 describes an amorphous form of Rifaximin which is prepared by dissolving Rifaximin in solvents such as alkyl esters, alkanols and ketones and precipitating by addition of anti-solvents selected from hydrocarbons, ethers or mixtures thereof.

U.S. Patent No. 8,193,196 describes two polymorphic forms of Rifaximin, designated δ and ε respectively. Form δ has water content within the range from 2.5 to 6% by weight (preferably from 3 to 4.5%).

U.S. Patent No 8,067,429 describes a-dry, β-1, β-2, ε-dry and amorphous forms of Rifaximin.

U.S. Patent No. 8,227,482 describes polymorphs Form μ, Form π, Form Omicron, Form Zeta, Form Eta, Form Iota and Form Xi of Rifaximin.

International application publications WO 2008/035109, WO 2008/155728, WO 2012/035544, WO 2012/060675, and WO 2012/156533 describes various amorphous or poorly crystalline forms of Rifaximin.

These polymorphic forms are obtained under different experimental conditions and are characterized by XRPD pattern.

The polymorphic forms of Rifaximin obtained from the prior art methods have specific water content. Transition between different polymorphic forms of Rifaximin occurs by drying or wetting of the synthesized Rifaximin. Hence, it is evident from above that Rifaximin can exist in number of polymorphic forms, formation of these polymorphic forms depends upon specific reaction conditions applied during crystallization and drying.

Rifaximin is a semi-synthetic, rifamycin-based non-systematic antibiotic. It is chemically termed as (2S,16Z,18E,20S,21S,22R,23R,24R,25S,26 S,27S, 28E)-5,6,21,23,255-pentahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca-[1,11,13]trienimino)benzofuro[4,5-e]pyrido[1,2-a]-benzimida-zole-1,15(2H)-dione,25-acetate (I).

Rifaximin is used for treatment of travelers’ diarrhea caused by noninvasive strains of Escherichia coli.

Rifaximin was first disclosed in US4341785 which also discloses a process for its preparation and a method for crystallization of rifaximin using suitable solvents or mixture of solvents. However, this patent does not mention the polymorphism of rifaximin.

Canadian patent CA1215976 discloses a process for the synthesis of imidazo rifamycins which comprises reacting rifamycin S with 2-amino-4-methyl pyridine.

US4557866 discloses a process for preparation of rifaximin, but does not mention the polymorphs of rifaximin.

US7045620 discloses crystalline polymorphic forms of rifaximin which are termed as rifaximin α, rifaximin β and rifaximin γ. These polymorphic forms are characterized using X-ray powder diffraction. Further this patent mentions that γ form is poorly crystalline with a high content of amorphous component. This patent also discloses processes for preparation of these polymorphs which involve use of processes of crystallization and drying as disclosed in US4557866along with control of temperature at which the product is crystallized, drying process, water content thereof. Further, according to this patent, crystal formation depends upon the presence of water within the crystallization solvent.

The above patent discloses rifaximin α which is characterized by water content lower than 4.5% & powder X-ray diffractogram having significant peaks are at values of diffraction angles 2θ of 6.6°; 7.4°; 7.9°, 8.8°, 10.5°, 11.1 °, 11.8°, 12.9°, 17.6°, 18.5°, 19.7°, 21.0°, 21.4°, 22.1°; rifaximin β which is characterized by water content higher than 4.5% & powder X-ray diffractogram having significant peaks are at values of diffraction angles 2θ of 5.4°; 6.4°; 7.0°, 7.8°, 9.0°, 10.4°, 13.1°, 14.4°, 17.1°, 17.9°, 18.3°, 20.9° and rifaximin γ which is characterized by poorer powder X-ray diffractogram because of poor crystallinity. The significant peaks are at values of diffraction angles 2θ of 5.0°; 7.1°; 8.4°.

US2005/0272754 also discloses polymorphs of rifaximin namely rifaximin α form, rifaximin β form & rifaximin γ form characterized by powder X-ray diffractogram, intrinsic dissolution rates and processes of preparation of polymorphic forms of rifaximin. However, none of the above patents disclose a wholly amorphous form of rifaximin.

It is a well known fact that different polymorphic forms of the same drug may have substantial differences in certain pharmaceutically important properties. The amorphous form of a drug may exhibit different dissolution characteristics and in some case different bioavailability patterns compared to crystalline forms.

Further, amorphous and crystalline forms of a drug may have different handling properties, dissolution rates, solubility, and stability.

Furthermore, different physical forms may have different particle size, hardness and glass transition temperatures. Amorphous materials do not exhibit the three-dimensional long-range orders found in crystalline materials, but are structurally more similar to liquids where the arrangement of molecules is random.

Amorphous solids do not give a definitive x-ray diffraction pattern (XRD). In addition, amorphous solids do not give rise to a specific melting point and tend to liquefy at some point beyond the glass transition temperature. Because amorphous solids do not have lattice energy, they usually dissolve in a solvent more rapidly and consequently may provide enhanced bioavailability characteristics such as a higher rate and extent of absorption of the compound from the gastrointestinal tract. Also, amorphous forms of a drug may offer significant advantages over crystalline forms of the same drug in the manufacturing process of solid dosage form such as compressibility.

Drugs Fut 1982,7(4),260

The reaction of rifamycin S (I) with pyridine perbromide (II) in 2-propanol/chloroform (70/30) mixture at 0 C gives 3-bromorifamicin S (III), which is then condensed with 2-amino-4-methyl-pyridine (IV) at 10 C. The o-quinoniminic compound (V) is then obtained. This compound is finally reduced with ascorbic acid.


	US 262123

The reaction of rifamycin S (I) with pyridine perbromide (II) in 2-propanol/chloroform (70/30) mixture at 0 C gives 3-bromorifamicin S (III), which is then condensed with 2-amino-4-methyl-pyridine (IV) at 10 C. The o-quinoniminic compound (V) is then obtained. This compound is finally reduced with ascorbic acid.

PATENT

https://www.google.com/patents/EP2069363B1?cl=e

The schematic representation for preparation of amorphous rifaximin is as follows :

Amorphous rifaximin according to the present invention can be characterized by various parameters like solubility, intrinsic dissolution, bulk density, tapped density.

Rifaximin is known to exist in 3 polymorphic Forms namely α Form, β Form & γ Form of which the α Form is thermodynamically the most stable. Hence, the amorphous form of rifaximin was studied in comparison with α Form.

Further, when intrinsic dissolution of amorphous rifaximin is carried out against the α Form, it is observed that the amorphous rifaximin has better dissolution profile than α Form which is shown in table below (this data is also shown graphically in Figure 3):

Dissolution medium : 1000 ml of 0.1M Sodium dihydrogen phosphate monohydrate + 4.5g of sodium lauryl sulphate

Temperature : 37±0.5°C

Rotation speed : 100 rpm

Particle size : Amorphous rifaximin – 11 microns

α Form of rifaximin – 13 microns

Time in minutes	% Release of Amorphous Rifaximin	% Release of α Form of Rifaximin
15	1.1	0.8
30	1.9	1.8
45	2.9	3.0
60	3.7	4.4
120	8.1	11.0
180	12.6	18.0
240	16.6	24.6
360	24.7	38.7
480	32.0	47.5
600	39.5	52.7
720	46.4	56.4
960	60.4	62.9
1200	72.9	67.8
1400	83.0	72.7

Amorphous rifaximin exhibits bulk density in the range of 0.3 – 0.4 g/ml and tapped density is in the range of 0.4 – 0.5 g/ml while the α Form rifaximin exhibits bulk density in the range of 0.2 – 0.3 g/ml & tapped density is in the range of 0.3 – 0.4 g/ml. These higher densities of amorphous rifaximin are advantageous in formulation specifically in tablet formulation, for example, it gives better compressibility.

CLIP

Rifaximin (CAS NO.: 80621-81-4), with other name of 4-Deoxy-4-methylpyrido[1,2-1,2]imidazo[5,4-c]rifamycin SV, could be produced through many synthetic methods.

Following is one of the reaction routes:

The reaction of rifamycin S (I) with pyridine perbromide (II) in 2-propanol/chloroform (70/30) mixture at 0 C gives 3-bromorifamicin S (III), which is then condensed with 2-amino-4-methyl-pyridine (IV) at 10 C. The o-quinoniminic compound (V) is then obtained. This compound is finally reduced with ascorbic acid.

POLYMORPHISM

Rifaximin (INN; see The Merck Index, XIII Ed., 8304) is an antibiotic belonging to the rifamycin class, exactly it is a pyrido-imidazo rifamycin described and claimed in Italian Patent IT 1154655, while European Patent EP 0161534 describes and claims a process for its production starting from rifamycin O (The Merck Index, XIII Ed., 8301).

Both these patents describe the purification of rifaximin in a generic way stating that crystallization can be carried out in suitable solvents or solvent systems and summarily showing in some examples that the reaction product can be crystallized from the 7:3 mixture of ethyl alcohol/water and can be dried both under atmospheric pressure and under vacuum without specifying in any way either the experimental conditions of crystallization and drying, or any distinctive crystallographic characteristic of the obtained product.

The presence of different polymorphs had just not been noticed and therefore the experimental conditions described in both patents had been developed with the goal to get a homogeneous product having a suitable purity from the chemical point of view, independent from the crystallographic aspects of the product itself.

It has now been found, unexpectedly, that there are several polymorphous forms whose formation, besides the solvent, depends on time and temperature conditions under which both crystallization and drying are carried out.

In the present application, these orderly polymorphous forms will be, later on, conventionally identified as rifaximin α (FIG. 1) and rifaximin β (FIG. 2) on the basis of their respective specific diffractograms, while the poorly crystalline form with a high content of amorphous component will be identified as rifaximin γ (FIG. 3).

Rifaximin polymorphous forms have been characterized through the technique of the powder X-ray diffraction.

The identification and characterization of these polymorphous forms and, simultaneously, the definition of the experimental conditions for obtaining them is very important for a compound endowed with pharmacological activity which, like rifaximin, is marketed as medicinal preparation, both for human and veterinary use. In fact it is known that the polymorphism of a compound that can be used as active ingredient contained in a medicinal preparation can influence the pharmaco-toxicologic properties of the drug. Different polymorphous forms of an active ingredient administered as drug under oral or topical form can modify many properties thereof like bioavailability, solubility, stability, colour, compressibility, flowability and workability with consequent modification of the profiles of toxicological safety, clinical effectiveness and productive efficiency.

What mentioned above is confirmed by the fact that the authorities that regulate the grant of marketing authorization of the drugs market require that the manufacturing methods of the active ingredients are standardized and controlled in such a way that they give homogeneous and sound results in terms of polymorphism of production batches (CPMP/QWP/96, 2003—Note for Guidance on Chemistry of new Active Substance; CPMP/ICH/367/96—Note for guidance specifications: test procedures and acceptance criteria for new drug substances and new drug products: chemical substances; Date for coming into operation: May 2000).

The need for the above-mentioned standardization has further been strengthened in the field of the rifamycin antibiotics by Henwood S. Q., de Villiers M. M., Liebenberg W. and Lotter A. P., Drug Development and Industrial Pharmacy, 26 (4), 403-408, (2000), who have ascertained that different production batches of the rifampicin (INN) made from different manufacturers differ from each other in that they show different polymorphous characteristics, and as a consequence they show different dissolution profiles, along with a consequent alteration of the respective pharmacological properties.

By applying the crystallization and drying processes generically disclosed in the previous patents IT 1154655 and EP 0161534 it has been found that under some experimental conditions a poorly crystalline form of rifaximin is obtained, while under other experimental conditions other polymorphic crystalline forms of Rifaximin are obtained. Moreover it has been found that some parameters, absolutely not disclosed in the above-mentioned patents, like for instance preservation conditions and the relative ambient humidity, have the surprising effect to determine the polymorph form.

The polymorphous forms of rifaximin object of the present patent application were never seen or hypothesized, while thinking that, whichever method was used within the range of the described condition, a sole homogeneous product would always have been obtained, irrespective of crystallizing, drying and preserving conditions. It has now been found that the formation of α, β and γ forms depends both on the presence of water within the crystallization solvent, on the temperature at which the product is crystallized and on the amount of water present in the product at the end of the drying phase. Form α, form β and form γ of rifaximin have then been synthesized and they are the object of the invention.

Moreover it has been found that the presence of water in rifaximin in the solid state is reversible, so that water absorption and/or release can take place in time in presence of suitable ambient conditions; consequently rifaximin is susceptible of transition from one form to another, also remaining in the solid state, without need to be again dissolved and crystallized. For instance polymorph α, getting water by hydration up to a content higher than 4.5%, turns into polymorph β, which in its turn, losing water by drying up to a content lower than 4.5%, turns into polymorph α.

These results have a remarkable importance as they determine the conditions of industrial manufacturing of some steps of working which could not be considered critical for the determination of the polymorphism of a product, like for instance the washing of a crystallized product, or the preservation conditions of the end product, or the characteristics of the container in which the product is preserved.

The above-mentioned α, β and γ forms can be advantageously used as pure and homogeneous products in the manufacture of medicinal preparations containing rifaximin.

As already said, the process for manufacturing rifaximin from rifamycin O disclosed and claimed in EP 0161534 is deficient from the point of view of the purification and identification of the product obtained; it shows some limits also from the synthetic point of view as regards, for instance, the very long reaction times, from 16 to 72 hours, not very suitable to an industrial use and moreover because it does not provide for the in situ reduction of rifaximin oxidized that may be formed within the reaction mixture.

Therefore, a further object of the present invention is an improved process for the industrial manufacturing of the α, β and γ forms of rifaximin, herein claimed as products and usable as defined and homogeneous active ingredients in the manufacture of the medicinal preparations containing such active ingredient.

PATENT

https://www.google.com/patents/US20090234114

FIG. 1 is a powder X-ray diffractogram of rifaximin polymorphic form α.

FIG. 2 is a powder X-ray diffractogram of rifaximin polymorphic form β.

FIG. 3 is a powder X-ray diffractogram of rifaximin polymorphic form γ.

PATENT

Patent US20130004576

Rifaximin (INN; see The Merck Index, XIII Ed., 8304, CAS no. 80621-81-4), IUPAC nomenclature (2S,16Z,18E,20S,21S,22R,23R,24R,25S,26S,27S,28E)-5,6,21,23,25 pentahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca-(1,11,13)trienimino)benzofuro(4,5-e)pyrido(1,2,-a)benzimidazole-1,15(2H)-dione,25-acetate) is a semi-synthetic antibiotic belonging to the rifamycin class of antibiotics. More precisely rifaximin is a pyrido-imidazo rifamycin described in the Italian patent IT 1154655, whereas the European patent EP 0161534 discloses a process for rifaximin production using rifamycin O as starting material (The Merck Index, XIII Ed., 8301).

U.S. Pat. No. 7,045,620, US 2008/0262220, US 7,612,199, US 2009/0130201 and Cryst. Eng. Comm., 2008, 10 1074-1081 (2008) disclose new forms of rifaximin.

WO 2008/035109 A1 discloses a process to prepare amorphous rifaximin, which comprises reaction of rifamycin S with 2-amino-4 picoline in presence of organic solvent like dichloromethane, ethylacetate, dichloroethylene, chloroform, in an inert atmosphere. When water is added to the reaction mixture, a solid precipitate corresponding to amorphous rifaximin is obtained.

The process described in this document can be assimilated to a crash precipitation, wherein the use of an anti-solvent causes the precipitation of rifaximin without giving any information about the chemical physical and biological characteristics of the rifaximin obtained.

WO 2009/108730 A2 describes different polymorphous forms of rifaximin and also amorphous forms of rifaximin. Amorphous forms are prepared by milling and crash precipitation and with these two different methods the amorphous rifaximin obtained from these two different processes has the same properties.

FIG. 4: ¹³C-NMR spectrum of rifaximin obtained by spray drying process.

FIG. 5: FT-IR spectrum of rifaximin obtained by spray drying process.

Patent

WO 2015014984

Rifaximin, lUPAC name:

(2S,16Z,18E,20S,21 S,22H,23H,24H,25S,26S,27S,28£)-5,6,21 ,23,25-pentahydroxy- 27-methoxy-2,4,1 1 ,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca-[1 ,1 1 ,13]-trienimmino)-benzofuro-[4,5-e]-pirido-[1 ,2-oc]-benzimidazol-1 , 15(2 -/)-dione,25-acetate, is the compound of formula (I):

Rifaximin is a broad-spectrum antibiotic belonging to the family of rifamycins, devoid of systemic activity. In view of its physicochemical properties, it is not adsorbed in the gastrointestinal tract and therefore exerts its antimicrobial action inside the gastrointestinal tract. Rifaximin therefore has applications in the treatment of diarrhoea and of microbial infections of the gastrointestinal tract typically caused by E. coli, a microorganism which, being incapable of passing through the mucosa of the gastrointestinal tract, remains in contact with the gastrointestinal fluids. Rifaximin also has applications for the treatment of irritable bowel syndrome, Crohn’s disease, diverticulitis and for antibiotic prophylaxis preceding surgical operations on the intestines.

Rifaximin was obtained and described for the first time in the EP161534 starting from rifamycin O and 2-amino-4-picoline in the presence of ethanol/water and

ascorbic acid/HCI to obtain raw rifaximin which is then treated with Ethanol/water to obtain crystallized rifaximin.

Polymorphic forms of rifaximin, and processes for their synthesis and purification, are described in various documents of the known art.

Rifaximin K was firstly described in WO2012/156951 . Such a crystalline form resulted to be more stable in the presence of humidity than the other known crystalline forms of rifaximin, thus enabling the storage, even for prolonged periods. Such a polymorph was obtained by a process starting from rifaximin comprising the following steps: -suspending or dissolving rifaximin in a 1 ,2-dimethoxyethane based solvent, recovering the product and drying to remove said 1 ,2-dimethoxyethane based solvent. In one of the embodiments of the invention 1 ,2-dimethoxyethane is used as the unique solvent of rifaximin, in other 1 ,2-dimethoxyethane is described as used in combination of n-heptane, methanol, acetonitrile, R-COO-R¹ esters wherein R and R¹ are independently C₃-C₆ alkyl radicals, and C₃-C₇ alkyl ketones, ethanol, isopropanol and water.

Paper

The synthesis of 4-deoxypyrido(1′,2′-1,2)imidazo(5,4-c)rifamycin SV derivatives
J Antibiot 1984, 37(12): 1611

LAST STEP DEPICTED AGAIN

Treatment of rifamycin S (I) with Pyr·Br2 in 2-PrOH/CHCl3 gives 3-bromorifamycin S (II) (1), which upon cyclocondensation with 2-amino-4-methyl-pyridine (III) (1,2,3) in CHCl3 (2) or EtOH (3) yields imine derivative (IV). Finally, reduction of (IV) with L-(+)- ascorbic acid (1,2,3) in MeOH (2) or EtOH (3) provides the target rifaximin (1,2,3).

PATENT

WO 2005044823, WO 2012035544, WO 2015014984

Rifaximin is prepared by the cyclocondensation of rifamycin-O with 2-amino-4-picoline in a solvent mixture such as acetone, acetonitrile, EtOH, MIBK, propylene glycol, i-PrOH or t-BuOH and H2O at 50 °C or EtOH/aceone/H2O or optionally in the presence of I2 in CH2Cl2

PATENT

WO 2015159275

The process is shown in the scheme given below:

Rifamycin-S

3-halo-Rifamycin-S

Examples

Example 1;

5g of Rifamycin S, 3.1 gms of 2-amino-4-methyl pyridine, 0.45 g of iodine, 1.65 ml of acetic acid and 20ml of acetonitrile were charged in a clean and dry round bottom flask followed by stirring the resultant reaction mixture at about 30°C for about 30 hours. The reaction progress was monitored by TLC, after completion of reaction, the reaction mass was quenched by adding a mixture of 4.0g of ascorbic acid dissolved in 20 ml of water. The resultant reaction suspension was stirred at about 25°C for about 15mins. 25 ml of dichloromethane was charged and stirred for about 15mins. followed by separation of organic and aqueous phases. The aqueous phase was extracted with 25 ml of dichloromethane followed by separation of organic and aqueous phases. The organic phases were combined and distilled at below about 50°C to yield Rifaximin as residue. 11.25ml of purified water and 11.25ml of ethanol were charged to the residue and stirred at about 30°C for about 15 mins. The resultant reaction

suspension was heated to about 75°C and stirred for about 30mins. The resultant reaction solution further cooled to about 25 °C and stirred for about 2 hours followed by further cooling to about 5°C for about 3 hours. The solid precipitated was filtered and the solid was washed with a mixture of 2.5ml of ethanol and 2.5 ml of purified water. The solid obtained was dried at about 50°C for about 10 hours to afford 3 g. of Rifaximin as crystalline form. Purity by HPLC: 99.85 area %.

PAPER

European journal of medicinal chemistry (2015), 103, 551-62

Patent

https://www.google.com/patents/WO2013027227A1?cl=en

Examples

Example 1 : Purification of Rifamycin S

Rifamycin S (500g) and Ethanol (1.5L) were stirred and refluxed for 1 hour. The reaction mixture was then cooled slowly to ambience, stirred at this temperature for 2 hour and filtered. The product dried in vacuum oven at 40 ^°C to obtain 475g of pure Rifamycin S showing the des acetyl impurity below to 0.6%.

Example 2: Preparation of rifaximin

Rifamycin S (300 g) was stirred in dichloromethane (900 ml) at room temperature for 15 minutes to get a clear solution and then 2-Amino-4-methyl pyridine (139.2g) was added at room temperature under nitrogen atmosphere. Iodine (57. Og) dissolved in dichloromethane (2100ml), was added drop wise in 30-45 minutes at room temperature. The reaction mass was stirred for 22-24 hours at 25-30 ^°C. After completion of the reaction, a 20% solution of L(-) ascorbic acid in water (300 ml) was added. The reaction mixture was stirred for 45-60 minutes at room temperature and then cooled to 10-15 ^°C. The pH of the resulting solution was adjusted to 1.5-2.0 with slow addition of dilute hydrochloric acid under stirring. The reaction mass was stirred for 15-20 minutes and layers were separated. The organic layer was washed with demineralized water (1500 ml), 10% sodium thiosulfate solution (1500 ml) and with demineralized water till pH was neutral. The solvent was distilled off under vacuum at 40-45 °C to get a residue which was taken in cyclohexane (1500 ml) and stirred for 1 hour. The resulting solid was filtered, washed with cyclohexane (300 ml) crystallized from a mixture of ethyl alcohol and water (600ml; 420ml ethyl alcohol and 180 ml water) to get 240g of crude rifaximin having purity 99.3% by HPLC.

Example 3: Preparation of rifaximin

Step-1: Preparation of crude rifaximin

Rifamycin S (300 g) was stirred in dichloromethane (900 ml) at room temperature for 15 minutes to get a clear solution and then 2-amino-4-methyl pyridine (139.2g) was added at room temperature under nitrogen atmosphere. Iodine (57. Og) dissolved in dichloromethane (2100ml), was added drop wise in 30-45 minutes at room temperature and was stirred for 22-24 hours. After completion of the reaction, a 20% solution of L (-) ascorbic acid in water (300 ml) was added and stirred for 45-60 minutes. The reaction mass was cooled to 10-15 ^°C and pH of the resulting solution was adjusted to 1.5-2.0 with slow addition of dilute hydrochloric acid under stirring. The reaction mass was stirred for 15-20 minutes and layers were separated and the organic layer was washed with demineralized water (1500 ml), with 10% sodium thiosulfate solution (1500 ml) and demineralized water till pH was neutral. The solvent was distilled off under vacuum at 40-45 °C to obtain a residue which was crystallized from a mixture of ethyl alcohol and water (378ml ethyl alcohol and 162 ml water) and dried at 35-40 °C to obtain 240g crude rifaximin having purity 98.8% by HPLC. Step-2: Purification of crude rifaximin

Crude rifaximin (240g) was stirred in dichloromethane (2400ml) at room temperature, a neutral alumina (240g) was added, stirred for 1 hour and filtered. The solvent was then distilled off and residue was treated with ethyl acetate (2400ml) and stirred to dissolution. The resulting residue was crystallized from a mixture of ethyl alcohol and water (302ml ethyl alcohol and 130ml water) and dried at 35-40 “C to obtain 192g of rifaximin having purity 99.8% by HPLC.

PATENT

https://www.google.com/patents/US9018225

PAPER

https://www.researchgate.net/profile/Miriam_Barbanti/publication/245268795_Viscomi_G_C_et_al_Crystal_forms_of_rifaximin_and_their_effect_on_pharmaceutical_properties_Cryst_Eng_Comm_10_1074-1081/links/556ec70d08aefcb861dba679.pdf

PATENTS

US4341785	May 11, 1981	Jul 27, 1982	Alfa Farmaceutici S.P.A.	Imidazo-rifamycin derivatives with antibacterial utility
US4557866	Apr 26, 1985	Dec 10, 1985	Alfa Farmaceutici S.P.A.	Process for the synthesis of pyrido-imidazo rifamycins
US7045620	Dec 5, 2003	May 16, 2006	Alfa Wassermann, S.P.A.	Polymorphous forms of rifaximin, processes for their production and use thereof in medicinal preparations
US7612199	Jun 4, 2009	Nov 3, 2009	Alfa Wassermann, S.P.A.	Polymorphic forms α, β, and γ of rifaximin
US7902206		Mar 8, 2011	Alfa Wassermann, S.P.A.	Polymorphic forms α, β and γ of rifaximin
US7906542	May 13, 2008	Mar 15, 2011	Alfa Wassermann, S.P.A.	Pharmaceutical compositions comprising polymorphic forms α, β, and γ of rifaximin
US7915275		Mar 29, 2011	Alfa Wassermann, S.P.A.	Use of polymorphic forms of rifaximin for medical preparations
US7923553		Apr 12, 2011	Alfa Wassermann, S.P.A.	Processes for the production of polymorphic forms of rifaximin
US7928115		Apr 19, 2011	Salix Pharmaceuticals, Ltd.	Methods of treating travelers diarrhea and hepatic encephalopathy
US8158644		Apr 17, 2012	Alfa Wassermann, S.P.A.	Pharmaceutical compositions comprising polymorphic forms α, β, and γ of rifaximin
US8158781	Mar 4, 2011	Apr 17, 2012	Alfa Wassermann, S.P.A.	Polymorphic forms α, β and γ of rifaximin
US8193196	Feb 27, 2006	Jun 5, 2012	Alfa Wassermann, S.P.A.	Polymorphous forms of rifaximin, processes for their production and use thereof in the medicinal preparations
US20050272754 *	May 24, 2005	Dec 8, 2005	Alfa Wassermann S.P.A.	Polymorphic forms of rifaximin, processes for their production and uses thereof

Reference
1		Viscomi, G. C., et al., “Crystal forms of rifaximin and their effect on pharmaceutical properties“, Cryst Eng Comm, 2008, 10, 1074-1081, (May 28, 2008), 1074-1081.

Citing Patent	Filing date	Publication date	Applicant	Title
US9186355	Mar 30, 2015	Nov 17, 2015	Novel Laboratories	Rifaximin crystalline forms and methods of preparation thereof

WO2008035109A1 *	Sep 24, 2007	Mar 27, 2008	Cipla Limited	Rifaximin
WO2009108730A2 *	Feb 25, 2009	Sep 3, 2009	Salix Pharmaceuticals, Ltd.	Forms of rifaximin and uses thereof
WO2011080691A1 *	Dec 27, 2010	Jul 7, 2011	Silvio Massimo Lavagna	Method for the production of amorphous rifaximin
EP1698630A1 *	Mar 3, 2005	Sep 6, 2006	ALFA WASSERMANN S.p.A.	New polymorphous forms of rifaximin, processes for their production and use thereof in the medicinal preparations
US20080262220 *	May 13, 2008	Oct 23, 2008	Giuseppe Claudio Viscomi	Polymorphic forms alpha, beta and gamma of rifaximin
US20090082558 *	Sep 20, 2007	Mar 26, 2009	Apotex Pharmachem Inc.	Amorphous form of rifaximin and processes for its preparation

* Cited by examiner

REFERENCED BY

Citing Patent	Filing date	Publication date	Applicant	Title
WO2015014984A1 *	Aug 1, 2014	Feb 5, 2015	Clarochem Ireland Ltd.	A process for preparing rifaximin k
CN103360357A *	Aug 7, 2013	Oct 23, 2013	中国药科大学	A simvastatin-gliclazide co-amorphous compound
US9359374	Jun 13, 2013	Jun 7, 2016	Apotex Pharmachem Inc.	Polymorphic forms of rifaximin

US4341785 *	May 11, 1981	Jul 27, 1982	Alfa Farmaceutici S.P.A.	Imidazo-rifamycin derivatives with antibacterial utility
US4557866 *	Apr 26, 1985	Dec 10, 1985	Alfa Farmaceutici S.P.A.	Process for the synthesis of pyrido-imidazo rifamycins
US7045620 *	Dec 5, 2003	May 16, 2006	Alfa Wassermann, S.P.A.	Polymorphous forms of rifaximin, processes for their production and use thereof in medicinal preparations

Citing Patent	Filing date	Publication date	Applicant	Title
US8518949	Jun 4, 2012	Aug 27, 2013	Alfa Wassermann S.P.A.	Polymorphous forms of rifaximin, processes for their production and use thereof in the medicinal preparations
US20140079783 *	Jul 3, 2013	Mar 20, 2014	Alfa Wassermann Spa	Pharmaceutical Compositions Comprising Rifaximin and Amino acids, Preparation Methods and Use Thereof
CN101836959A *	May 20, 2010	Sep 22, 2010	山东达因海洋生物制药股份有限公司	Method for preparing almost bitterless rifaximin dry suspension
CN103269587A *	Jun 3, 2011	Aug 28, 2013	萨利克斯药品有限公司	New forms of rifaximin and uses thereof
WO2011153444A1 *	Jun 3, 2011	Dec 8, 2011	Salix Pharmaceuticals, Ltd	New forms of rifaximin and uses thereof

References

Xifaxan label information PDF Retrieved November 15, 2008.
DuPont, H (2007). “Therapy for and Prevention of Traveler’s Diarrhea”. Clinical Infectious Diseases 45 (45 (Suppl 1)): S78–S84. doi:10.1086/518155. PMID 17582576.
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Martinez-Sandoval F, Ericsson CD, Jiang ZD, Okhuysen PC, Romero JH, Hernandez N, Forbes WP, Shaw A, Bortey E, DuPont HL (Mar–Apr 2010). “Prevention of travelers’ diarrhea with rifaximin in US travelers to Mexico.”. J Travel Med. 17 (2): 111–7.doi:10.1111/j.1708-8305.2009.00385.x. PMID 20412178.
Sharara A, Aoun E, Abdul-Baki H, Mounzer R, Sidani S, ElHajj I (2006). “A randomized double-blind placebo-controlled trial of rifaximin in patients with abdominal bloating and flatulence”. Am J Gastroenterol 101 (2): 326–33. doi:10.1111/j.1572-0241.2006.00458.x.PMID 16454838.
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http://www.hc-sc.gc.ca/dhp-mps/prodpharma/sbd-smd/drug-med/sbd_smd_2013_zaxine_161256-eng.php

External links

FDA label approved for Xifaxan (PDF warning)
Xifaxan200 (manufacturer’s website)

Patents

Patent Number	Pediatric Extension	Approved	Expires (estimated)
US6861053	No	1999-08-11	2019-08-11
US7045620	No	2004-06-19	2024-06-19
US7452857	No	1999-08-11	2019-08-11
US7605240	No	1999-08-11	2019-08-11
US7612199	No	2004-06-19	2024-06-19
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US7902206	No	2004-06-19	2024-06-19
US7906542	No	2005-06-01	2025-06-01
US7915275	No	2005-02-23	2025-02-23
US7928115	No	2009-07-24	2029-07-24
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US8518949	No	2006-02-27	2026-02-27
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Properties

Rifaximin
Systematic (IUPAC) name


(2S,16Z,18E,20S,21S,22R,23R,24R,25S,26S,27S,28E)-5,6,21,23,25-pentahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca-[1,11,13]trienimino)benzofuro [4,5-e]pyrido[1,2-a]-benzimida-zole-1,15(2H)-dione,25-acetate
Clinical data
Trade names	Xifaxan, Xifaxanta, Normix, Rifagut
AHFS/Drugs.com	Monograph
MedlinePlus	a604027
Pregnancy category	US: C (Risk not ruled out)
Routes of administration	Oral
Legal status
Legal status	℞ (Prescription only)
Pharmacokinetic data
Bioavailability	< 0.4%
Metabolism	Hepatic
Biological half-life	6 hours
Excretion	Fecal (97%)
Identifiers
CAS Number	80621-81-4
ATC code	A07AA11 (WHO) D06AX11(WHO) QG51AA06 (WHO)QJ51XX01 (WHO)
PubChem	CID 6436173
DrugBank	DB01220
ChemSpider	10482302
UNII	L36O5T016N
KEGG	D02554
ChEBI	CHEBI:75246
ChEMBL	CHEMBL1617
Chemical data
Formula	C₄₃H₅₁N₃O₁₁
Molar mass	785.879 g/mol

Giuseppe Viscomi, Manuela Campana, Dario Braga, Donatella Confortini, Vincenzo Cannata, Paolo Righi, Goffredo Rosini, “Polymorphic forms of rifaximin, processes for their production and uses thereof.” U.S. Patent US20050272754, issued December 08, 2005.

US20050272754

Title: Rifaximin

CAS Registry Number: 80621-81-4

CAS Name: (2S,16Z,18E,20S,21S,22R,23R,24R,25S,26R,27S,28E)-25-(Acetyloxy)-5,6,21,23-tetrahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca[1,11,13]trienimino)benzofuro[4,5-e]pyrido[1,2-a]benzimidazole-1,15(2H)-dione

Additional Names: 4-deoxy-4¢-methylpyrido[1¢,2¢-1,2]imidazo[5,4-c]rifamycin SV; rifamycin L 105; rifaxidin

Manufacturers’ Codes: L-105

Trademarks: Fatroximin (Fatro); Flonorm (Schering-Plough); Normix (Alfa); Rifacol (Formenti); Xifaxan (Salix)

Molecular Formula: C43H51N3O11

Molecular Weight: 785.88

Percent Composition: C 65.72%, H 6.54%, N 5.35%, O 22.39%

Literature References: Nonabsorbable semisynthetic rifamycin antibiotic. Prepn: BE 888895; E. Marchi, L. Montecchi, US4341785 (1981, 1982 both to Alfa); E. Marchi et al., J. Med. Chem. 28, 960 (1985); and NMR study: M. Brufani et al., J. Antibiot.37, 1611 (1984). X-ray crystal structure: idem et al., ibid. 1623. In vitro and in vivo antibacterial activity: A. P. Venturini, E. Marchi,Chemioterapia 5, 257 (1986). Toxicological study: G. Borelli, D. Bertoli, ibid. 263. Clinical trial in travelers’ diarrhea: R. Steffen et al., Am. J. Gastroenterol. 98, 1073 (2003). Review of activity, pharmacokinetics and clinical experience in gastrointestinal infections: J. C. Gillis, R. N. Brogden, Drugs 49, 467-484 (1995); D. B. Huang, H. L. DuPont, J. Infection 50, 97-106 (2005).

Properties: Red orange powder, mp 200-205° (dec). uv max: 232, 260, 292, 320, 370, 450 nm (E1%1cm 489, 339, 295, 216, 119, 159). Sol in alcohols, ethyl acetate, chloroform, toluene. Insol in water. LD50 orally in rats: >2000 mg/kg (Borelli, Bertoli).

Melting point: mp 200-205° (dec)

Absorption maximum: uv max: 232, 260, 292, 320, 370, 450 nm (E1%1cm 489, 339, 295, 216, 119, 159)

Toxicity data: LD50 orally in rats: >2000 mg/kg (Borelli, Bertoli)

Therap-Cat: Antibacterial.

Therap-Cat-Vet: Antibacterial.

Keywords: Antibacterial (Antibiotics); Ansamycins.

MORE…….

Rifaximin, alpha-0817185, L-105, Xifaxan, Lumenax, Flonorm, RedActiv, Rifacol, Normix

Drug Name	XIFAXAN
Application Number	021 361	Number	001
Active ingredients	RIFAXIMIN	Market Status	prescription
Dosage form or route of administration	TABLET; ORAL	specification	200MG
Treatment equivalent code		Drug Reference	Yes
Date of approval	2004/05/25	The applicant	SALIX PHARMACEUTICALS INC
Chemistry	New molecular entity (NME)	Review Categories	Standard review drug

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Patent No	Patent expiration date	Whether the compound patent	Whether or not product patents	Patents purpose code	Patent Download
7928115	2029/07/24			U-1121	PDF format
8741904	2026/02/27	Y		U-1526	PDF format
7612199	2024/06/19	Y	Y		PDF format
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History Patent Information
7045620	2024/05/22	Y			PDF format
8642573	2029/10/02			U-1481	PDF format

Related to this product market exclusivity protection information
Exclusivity Code	Expiration date
no
Historical market exclusivity protection information
NCE	2009/05/25

And information related to drug registration
Application Number	Amendment No.	Approval Conclusion	Disclosure Document Type	Document creation time	Obtaining Documentation
021 361	013	AP	Label	2014/03/13	download
021 361	013	AP	Letter	2014/03/14	download
021 361	012	AP	Letter	2015/05/28	download
021 361	012	AP	Label	2015/05/29	download
021 361	011	AP	Label	2010/03/05	download
021 361	011	AP	Letter	2010/03/08	download
021 361	009	AP	Label	2010/11/17	download
021 361	009	AP	Letter	2010/11/18	download
021 361	006	AP	Label	2007/02/02	download
021 361	006	AP	Letter	2007/02/12	download
021 361	000	AP	Letter	2004/06/01	download
021 361	000	AP	Label	2004/06/01	download
021 361	000	AP	Review	2004/08/27	download

Regulatory approval history information
Application Number	Amendment No.	Approval Conclusion	Approval Date	Approval of the content
021 361	016	AP	2015/10/15	Manufacturing Change or Addition
021 361	015	AP	2016/06/16	Manufacturing Change or Addition
021 361	014	AP	2015/04/23	Manufacturing Change or Addition
021 361	013	AP	2014/03/12	Labeling Revision
021 361	012	AP	2015/05/27	Efficacy Supplement with Clinical Data to Support
021 361	011	AP	2010/03/03	Labeling Revision
021 361	009	AP	11/15/2010	Labeling Revision
021 361	006	AP	2007/01/30	Labeling Revision
021 361	000	AP	2004/05/25	Approval

///////Rifaximin, Rifaxidin, Rifacol, Xifaxan, Normix, Rifamycin L 105, 80621-81-4, Rifaximin, alpha-0817185, L-105, Xifaxan, Lumenax, Flonorm, RedActiv, Rifacol, Normix

CC1C=CC=C(C(=O)NC2=C(C3=C(C4=C(C(=C3O)C)OC(C4=O)(OC=CC(C(C(C(C(C(C1O)C)O)C)OC(=O)C)C)OC)C)C5=C2N6C=CC(=CC6=N5)C)O)C

NINTEDANIB

Uncategorized Comments Off

Jul 062016

NINTEDANIB, BBIF 1120, Intedanib

Boehringer Ingelheim Corp

As a potential treatment for a range of different solid tumour types

CAS 656247-17-5

CAS 1377321-64-6 (nintedanib bisethanesulfonate)

CAS [656247-18-6] mono ethane sulfonate

3(Z)-[1-[4-[N-Methyl-N-[2-(4-methylpiperazin-1-yl)acetyl]amino]phenylamino]-1-phenylmethylene]-2-oxo-2,3-dihydro-1H-indole-6-carboxylic acid methyl ester

MW 539.62, MF C₃₁ H₃₃ N₅ O₄

Launched 2014 USA….Idiopathic pulmonary fibrosis

chinese, japanese

尼达尼布ニンテダニブ

ChemSpider 2D Image | Nintedanib esylate | C33H39N5O7S

Ethanesulfonic acid – methyl (3Z)-3-{[(4-{methyl[(4-methyl-1-piperazinyl)acetyl]amino}phenyl)amino](phenyl)methylene}-2-oxo-6-indolinecarboxylate (1:1)

Nintedanib esylate

Cas 656247-18-6 [RN]

Methyl (3Z)-3-[({4-[N-methyl-2-(4-methylpiperazin-1-yl)acetamido]phenyl}amino)(phenyl)methylidene]-2-oxo-2,3-dihydro-1H-indole-6-carboxylate ethanesulfonate

Nintedanib esylate [USAN]

(3Z)-2,3-Dihydro-3-[[[4-[methyl[2-(4-methyl-1-piperazinyl)acetyl]amino]phenyl]amino]phenylmethylene]-2-oxo-1H-indole-6-carboxylic acid methyl ester ethanesulfonate

1H-Indole-6-carboxylic acid, 2,3dihydro-3-[[[4-[methyl[(4-methyl-1-piperazinyl)acetyl]amino]phenyl]amino]phenylmethylene]-2-oxo-,methyl ester, (3Z)-, ethanesulfonate (1:1)

Nintedanib esylate, 656247-18-6, UNII-42F62RTZ4G, , NSC753000, NSC-753000, KB-62821

Molecular Formula: C₃₃H₃₉N₅O₇S Molecular Weight: 649.75706

ニンテダニブエタンスルホン酸塩

Highly crystalline (mp = 305 °C) and exhibits a log P of 3.0 and good aqueous solubility (>20 mg/mL in water)…..J. Med. Chem., 2015, 58 (3), pp 1053–1063

Nintedanib esilate is a bright yellow powder soluble in water. The solubility increases at lower pH and decrease at higher pH due to the non-protonated free base which has a low solubility in water.At room temperature, the active substance exists only in one single crystalline form . The active substance contains no chiral centres. The double bond at C

-3 of the indole moiety allows forE/Zisomerism, but the activesubstance is the Z

-isomer……….http://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Public_assessment_report/human/002569/WC500179972.pdf

Trade Name：Ofev^® / Vargatef^®

MOA：Tyrosine kinase inhibitor

Indication：Idiopathic pulmonary fibrosis (IPF); Non small cell lung cancer (NSCLC)

In 2011, orphan drug designation was assigned in the U.S. and Japan for the treatment of idiopathic pulmonary fibrosis. In 2013, orphan drug designation was also assigned for the same indication in the E.U. In 2014, a Breakthrough Therapy Designation was assigned to the compound for the treatment of idiopathic pulmonary fibrosis.

Nintedanib (formerly BIBF 1120) is a small molecule tyrosine-kinase inhibitor, targeting vascular endothelial growth factor receptor (VEGFR), fibroblast growth factor receptor (FGFR) and platelet derived growth factor receptor (PDGFR) being developed by Boehringer Ingelheim as an anti-angiogenesis anti-cancer agent under the trade name Vargatef, and recently approved for treatment of idiopathic pulmonary fibrosis as Ofev.

The use of nintedanib or its salts, particularly its esylate salt is claimed for treating non-small cell lung cancer (NSCLC) in a patient who has received prior treatment with an anti-tumor therapy other than with nintedanib, wherein the patient to be treated is selected for treatment on the basis showing progression of the cancer within a period of 9 months or less after the initiation of said prior treatment. It is also claimed that the compound may be administered in combination with an anti-cancer drug, eg docetaxel. Nintedanib is known to be an antagonist of FGF-1, FGF-2, FGF-3, VEGF-1, VEGF-2, VEGF-3, PDGF-α and PDGF-β receptors.

Use of nintedanib for the treatment of non-small cell lung cancer in a patient who has received prior anti-tumour therapy other than with nintedanib. Boehringer Ingelheim has developed and launched Ofev, an oral capsule formulation of nintedanib, for the treatment of idiopathic pulmonary fibrosis (IPF), hepatic insufficiency and cancer, including metastatic NSCLC, ovarian, prostate and colorectal cancer. In October 2014, the US FDA approved the drug and an NDA was filed in Japan for IPF. Picks up from WO2014049099, claiming pharmaceutical combinations comprising nintedanib and sunitinib.

Nintedanib is an indolinone derivative angiogenesis inhibitor, originated at Boehringer Ingelheim. In 2014, the product candidate was approved and launched in the U.S. for the treatment of idiopathic pulmonary fibrosis, and a positive opinion was received by the EMA for the same indication. Also in 2014, Nintedanib was approved in the E.U. for the oral treatment of locally advanced, metastatic or locally recurrent non-small cell lung cancer (NSCLC) of adenocarcinoma tumour histology after first-line chemotherapy, in combination with docetaxel.The drug candidate is a small-molecule triple kinase inhibitor targeting the angiogenesis kinases (angiokinases) vascular endothelial growth factor receptor (VEGFR), fibroblast growth factor receptor (FGFR) and platelet-derived growth factor receptor (PDGFR). By allowing the vascularization necessary for the nourishment of tumors, these angiokinases have been implicated in tumor growth, proliferation and metastasis. In previous studies, intedanib potently and selectively inhibited human endothelial cell proliferation and induced apoptosis in human umbilical vein endothelial cells (HUVEC). It showed good oral bioavailability and tolerance, and significant antitumor activity was observed in a number of human tumor xenograft models.

Mechanism of action

Nintedanib is an indolinone-derived drug that inhibits the process of blood vessel formation (angiogenesis). Angiogenesis inhibitors stop the formation and reshaping of blood vessels in and around tumours, which reduces the tumour’s blood supply, starving tumour cells of oxygen and nutrients leading to cell death and tumour shrinkage. Unlike conventional anti-cancer chemotherapy which has a direct cell killing effect on cancer cells, angiogenesis inhibitors starve the tumour cells of oxygen and nutrients which results in tumour cell death. One of the advantages of this method of anti-cancer therapy is that it is more specific than conventional chemotherapy agents, therefore results in fewer and less severe side effects than conventional chemotherapy.

The process of new blood vessel formation (angiogenesis) is essential for the growth and spread of cancers. It is mediated by signaling molecules (growth factors) released from cancer cells in response to low oxygen levels. The growth factors cause the cells of the tumour’s blood vessel to divide and reorganize resulting in the sprouting of new vessels in and around the tumour, improving its blood supply.

Angiogenesis is a process that is essential for the growth and spread of all solid tumours, blocking it prevents the tumour from growing and may result in tumour shrinkage as well as a reduction in the spread of the cancer to other parts of the body. Nintedanib exerts its anti-cancer effect by binding to and blocking the activation of cell receptors involved in blood vessel formation and reshaping (i.e. VEGFR 1-3, FGFR 1-3 AND PDGFRα and β). Inhibition of these receptors in the cells that make up blood vessels (endothelial cells, smooth muscle cells and pericytes) by Nintedanib leads to programmed cell death, destruction of tumor blood vessels and a reduction in blood flow to the tumour. Reduced tumour blood flow inhibits tumor cell proliferation and migration hence slowing the growth and spread of the cancer.^[1]

Adverse effects

Preclinical studies have shown that nintedanib binds in a highly selective manner to the ATP binding pocked of its three target receptor families, without binding to similarly shaped ATP domains in other proteins, which reduces the potential for undesirable side effects.^[2]

The most common side effects observed with nintedanib were reversible elevation in liver enzymes (10-28% of patients) and gastrointestinal disturbance (up to 50%). Side effects observed with nintedanib were worse with the higher 250 mg dose, for this reason subsequent trials have used the equally clinically effective 200 mg dose.^[1]^[2]^[3]^[4]^[5]^[6]^[7]^[8]^[9]

Nintedanib inhibits the growth and reshaping of blood vessels which is also an essential process in normal wound healing and tissue repair. Therefore a theoretical side effect of nintedanib is reduced wound healing however, unlike other anti-angiogenic agents, this side effect has not been observed in patients receiving nintedanib.

Studies

Preclinical studies have demonstrated that nintedanib selectively binds to and blocks the VEGF, FGF and PDGF receptors, inhibiting the growth of cells that constitute the walls of blood vessels (endothelial and smooth muscle cells and pericytes) in vitro. Nintedanib reduces the number and density of blood vessels in tumours in vivo, resulting in tumour shrinkage.^[1]^[2] Nintedanib also inhibits the growth of cells that are resistant to existing chemotherapy agents in vitro, which suggests a potential role for the agent in patients with solid tumours that are unresponsive to or relapse following current first line therapy.^[10]

Early clinical trials of nintedanib have been carried out in patients with non-small cell lung, colorectal, uterine, endometrial, ovarian and cervical cancer and multiple myeloma.^[4]^[5]^[7]^[8]^[9] These studies reported that the drug is active in patients, safe to administer and is stable in the bloodstream. They identified that the maximum tolerated dose of nintedanib is 20 0 mg when taken once a day.

Clinical studies

In the first human trials, nintedanib halted the growth of tumours in up to 50% of patients with non-small cell lung cancer and 76% of patients with advanced colorectal cancer and other solid tumours.^[4]^[8] A complete response was observed in 1/26 patients with non-small cell lung and 1/7 patients with ovarian cancer treated with nintedanib. A further 2 patients with ovarian cancer had partial responses to nintedanib.^[8]^[9]

Two phase II trials have been carried out assessing the efficacy, dosing and side effects of nintedanib in non-small cell lung and ovarian cancer. These trials found that nintedanib delayed relapse in patients with ovarian cancer by two months^[6] and that overall survival of patients with non-small cell lung who received nintedanib was similar to that observed with the FDA approved VEGFR inhibitor sorafenib. These trials also concluded that increasing the dose of the nintedanib has no effect on survival.^[3]

SYNTHESIS

WO2009071523A1

NINTEDANIB JYOJO

MORE SYNTHESIS

Route 1

Reference：1. WO0127081A1.

2. US6762180B1.

3. J. Med. Chem. 2009, 52, 4466-4480.

Route 2

Reference：1. WO2009071523A1 / US8304541B2.

Route 3

Reference：1. CN104262232A.

Route 4

Reference：1. CN104844499A.

Current clinical trials

Nintedanib is being tested in several phase I to III clinical trials for cancer. Angiogenesis inhibitors such as nintedanib may be effective in a range of solid tumour types including; lung, ovarian, metastatic bowel, liver and brain cancer. Patients are also being recruited for three phase III clinical trials that will evaluate the potential benefit of nintedanib when added to existing 1st line treatments in patients with ovarian.^[11] and 2nd line treatment in non-small cell lung cancer ^[12]^[13] The phase III trials of nintedanib in lung cancer have been named LUME-Lung 1 and LUME-Lung 2.

Current phase II trials are investigating the effect of nintedanib in patients with metastatic bowel cancer, liver cancer and the brain tumour: glioblastoma multiforme.^[14]

Phase III trials are investigating the use of nintedanib in combination with the existing chemotherapy agents permexetred and docetaxel in patients with non-small cell lung cancer,^[15] and in combination with carboplatin and paclitaxel as a first line treatment for patients with ovarian cancer.^[16]

A phase III clinical trial was underway examining the safety and efficacy of nintedanib on patients with the non-cancerous lung condition idiopathic pulmonary fibrosis.^[17] Nintedanib, under the brand name Ofev, was approved by the FDA for treatment of idiopathic pulmonary fibrosis on 15 Oct 2014. ^[18]

In terms of clinical development, additional phase III clinical trials are ongoing for the treatment of epithelial ovarian cancer, fallopian tube or primary peritoneal cancer, in combination with chemotherapy, and for the treatment of refractory metastatic colorectal cancer. Phase II clinical trials are also ongoing at the company for the treatment of glioblastoma multiforme, previously untreated patients with renal cell cancer, and for the treatment of patients with unresectable malignant pleural mesothelioma. The National Cancer Center of Korea (NCC) is evaluating the compound in phase II studies as second line treatment for small cell lung cancer (SCLC). The Centre Oscar Lambret is also conducting phase II clinical trials for the treatment of breast cancer in combination with docetaxel. Phase II trials are under way at EORTC as second line therapy for patients with either differentiated or medullary thyroid cancer progressing after first line therapy. The compound is also in early clinical development for the treatment of cancer of the peritoneal cavity, hepatocellular carcinoma, acute myeloid leukemia and ovarian cancer. Clinical trials have been completed for the treatment of prostate cancer and for the treatment of colorectal cancer. Boehringer Ingelheim is also conducting phase I/II clinical trials for the treatment of NSCLC and acute myeloid leukemia in addition to low-dose cytarabine. Phase I clinical studies are ongoing at the company for the treatment of epithelial ovary cancer and for the treatment of patients with mild and moderate hepatic impairment. The company had been evaluating the compound in early clinical trials for the treatment of prostate cancer in combination with docetaxel, but recent progress reports for this indication are not available at present.

PAPER

http://pubs.acs.org/doi/full/10.1021/jm501562a

Nintedanib: From Discovery to the Clinic

Gerald J. Roth^*†, Rudolf Binder§, Florian Colbatzky‡, Claudia Dallinger∥, Rozsa Schlenker-Herceg^○, Frank Hilberg^∇, Stefan-Lutz Wollin⊥, and Rolf Kaiser#

^†Department of Medicinal Chemistry; ^§Department of Drug Metabolism and Pharmacokinetics; ^‡Department of Non-Clinical Drug Safety; ^∥Department of Translational Medicine and Clinical Pharmacology; ^⊥Department of Respiratory Diseases Research; and ^#Corporate Division Medicine, TA Oncology, Boehringer Ingelheim Pharma GmbH & Co. KG, 88397 Biberach an der Riss, Germany

^○ Clinical Development and Medical Affairs, Respiratory, Boehringer Ingelheim Inc., Ridgefield, Connecticut 06877, United States

^∇ Boehringer Ingelheim RCV GmbH & Co. KG, A-1121 Vienna, Austria

J. Med. Chem., 2015, 58 (3), pp 1053–1063

DOI: 10.1021/jm501562a

Nintedanib (BIBF1120) is a potent, oral, small-molecule tyrosine kinase inhibitor, also known as a triple angiokinase inhibitor, inhibiting three major signaling pathways involved in angiogenesis. Nintedanib targets proangiogenic and pro-fibrotic pathways mediated by the VEGFR family, the fibroblast growth factor receptor (FGFR) family, the platelet-derived growth factor receptor (PDGFR) family, as well as Src and Flt-3 kinases. The compound was identified during a lead optimization program for small-molecule inhibitors of angiogenesis and has since undergone extensive clinical investigation for the treatment of various solid tumors, and in patients with the debilitating lung disease idiopathic pulmonary fibrosis (IPF). Recent clinical evidence from phase III studies has shown that nintedanib has significant efficacy in the treatment of NSCLC, ovarian cancer, and IPF. This review article provides a comprehensive summary of the preclinical and clinical research and development of nintedanib from the initial drug discovery process to the latest available clinical trial data.

Roth, G. J.; Heckel, A.; Colbatzky, F.; Handschuh, S.; Kley, J.; Lehmann-Lintz, T.; Lotz, R.; Tontsch-Grunt,U.; Walter, R.; Hilberg, F.Design, synthesis, and evaluation of indolinones as triple angiokinase inhibitors and the discovery of a highly specific 6-methoxycarbonyl-substituted indolinone (BIBF 1120) J. Med. Chem.2009, 52, 4466– 4480
2.Roth, G. J.; Sieger, P.; Linz, G.; Rall, W.; Hilberg, F.; Bock, T. 3-Z-[1-(4-(N-((4-Methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone monoethanesulphonate and the use thereof as a pharmaceutical composition. WO2004/013099. 2004.
3.Merten, J.; Linz, G.; Schnaubelt, J.; Schmid, R.; Rall, W.; Renner, S.; Reichel, C.; Schiffers, R. Process for the manufacture of an indolinone derivative. WO2009/071523. 2009

PAPER

http://pubs.acs.org/doi/abs/10.1021/jm900431g

J. Med. Chem., 2009, 52 (14), pp 4466–4480

DOI: 10.1021/jm900431g

Inhibition of tumor angiogenesis through blockade of the vascular endothelial growth factor (VEGF) signaling pathway is a new treatment modality in oncology. Preclinical findings suggest that blockade of additional pro-angiogenic kinases, such as fibroblast and platelet-derived growth factor receptors (FGFR and PDGFR), may improve the efficacy of pharmacological cancer treatment. Indolinones substituted in position 6 were identified as selective inhibitors of VEGF-, PDGF-, and FGF-receptor kinases. In particular, 6-methoxycarbonyl-substituted indolinones showed a highly favorable selectivity profile. Optimization identified potent inhibitors of VEGF-related endothelial cell proliferation with additional efficacy on pericyctes and smooth muscle cells. In contrast, no direct inhibition of tumor cell proliferation was observed. Compounds 2 (BIBF 1000) and 3 (BIBF 1120) are orally available and display encouraging efficacy in in vivo tumor models while being well tolerated. The triple angiokinase inhibitor 3 is currently in phase III clinical trials for the treatment of nonsmall cell lung cancer.

PATENT

WO-2014180955

The present invention relates to a beneficial treatment of tumours in patients suffering from NSCLC, and to a clinical marker useful as predictive variable of the responsiveness of tumours in patients suffering from NSCLC. The present invention further relates to a method for selecting patients likely to respond to a given therapy, wherein said method optionally comprises the use of a specific clinical marker. The present invention further relates to a method for delaying disease progression and/or prolonging patient survival of NSCLC patients, wherein said method comprises the use of a specific clinical marker.

The monoethanesulphonate salt form of this compound presents properties which makes this salt form especially suitable for development as medicament. The chemical structure of 3-Z-[l-(4-(N-((4-methyl-piperazin-l-yl)-methylcarbonyl)-N-methyl-amino)-anilino)- 1 -phenyl-methylene] -6-methoxycarbonyl-2-indolinone-monoethanesulphonate (ΓΝΝ name nintedanib esylate) is depicted below as Formula Al .

Formula Al

This compound is thus for example suitable for the treatment of diseases in which angiogenesis or the proliferation of cells is involved. The use of this compound for the treatment of immunologic diseases or pathological conditions involving an

immunologic component is being described in WO 2004/017948, the use for the treatment of, amongst others, oncological diseases, alone or in combination, is being described in WO 2004/096224 and WO 2009/147218, and the use for the treatment of fibrotic diseases is being described in WO 2006/067165.

A method using biomarkers for monitoring the treatment of an individual with the compound 3-Z-[l-(4-(N-((4-methyl-piperazin-l-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-l -phenyl-methylene] -6-methoxycarbonyl-2-indolinone or a pharmaceutically acceptable salt thereof, wherein it is determined if a sample from said individual comprises a biomarker in an amount that is indicative for said treatment, is disclosed in WO 2010/103058.

PATENT

http://www.google.com/patents/US20110201812

The present invention relates to a process for the manufacture of a specific indolinone derivative and a pharmaceutically acceptable salt thereof, namely 3-Z-[1-(4-(N-((4-methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone and its monoethanesulfonate, to new manufacturing steps and to new intermediates of this process.

The indolinone derivative 3-Z-[1-(4-(N-((4-methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone and its monoethanesulfonate are known from the following patent applications: WO 01/027081, WO 04/013099, WO 04/017948, WO 04/096224 and WO 06/067165. These patent applications disclose the compound, a process for its manufacture, a specific salt form of this compound and the use of the compound or its salt in a pharmaceutical composition to treat oncological or non-oncological diseases via inhibition of the proliferation of target cells, alone or in combination with further therapeutic agents. The mechanism of action by which the proliferation of the target cells occurs is essentially a mechanism of inhibition of several tyrosine kinase receptors, and especially an inhibition of the vascular endothelial growth factor receptor (VEGFR).

Figure US20110201812A1-20110818-C00001

Figure US20110201812A1-20110818-C00003

Figure US20110201812A1-20110818-C00004

EXAMPLE 1Synthesis of the 6-methoxycarbonyl-2-oxindole in accordance with the process shown in synthesis scheme CSynthesis of benzoic acid, 4-chloro-3-nitro-, methylester

- 20 kg of 4-chloro-3-nitro-benzoic acid (99.22 mol) is suspended in 76 L methanol. 5.9 kg thionylchloride (49.62 mol) is added within 15 minutes and refluxed for about 3 hours. After cooling to about 5° C., the product is isolated by centrifugation and drying at 45° C.
- Yield: 19.0 kg (88.8% of theoretical amount)
- Purity (HPLC): 99.8%

Synthesis of propanedioic acid, [4-(methoxycarbonyl)-2-nitrophenyl]-, dimethylester

- 12.87 kg of malonic acid, dimethylester (97.41 mol) is added to a hot solution (75° C.) of 10.73 kg sodium-tert.amylate (97.41 mol) in 35 L 1-methyl-2-pyrrolidinone (NMP). A solution of 10 kg benzoic acid, 4-chloro-3-nitro-, methylester (46.38 mol) in 25 L 1-methyl-2-pyrrolidinone is added at 75° C. After stirring for 1.5 hours at about 75° C. and cooling to 20° C., the mixture is acidified with 100 L diluted hydrochloric acid to pH 1. After stirring for 1.5 hours at about 5° C., the product is isolated by centrifugation and drying at 40° C.
- Yield: 13.78 kg (95.4% of theoretical amount)
- Purity (HPLC): 99.9%
- Alternatively, propanedioic acid, [4-(methoxycarbonyl)-2-nitrophenyl]-, dimethylester can be synthesized as follows:
- 33.1 kg of malonic acid, dimethylester (250.6 mol) and 27.0 kg benzoic acid, 4-chloro-3-nitro-, methylester (125.3 mol) are subsequently added to a solution of 45.1 kg sodium-methylate (250.6 mol) in 172 kg 1-methyl-2-pyrrolidinone (NMP) at 20° C. After stirring for 1.5 hours at about 45° C. and cooling to 30° C., the mixture is acidified with 249 L diluted hydrochloric acid. At the same temperature, the mixture is seeded, then cooled to 0° C. and stirred for an additional hour. The resulting crystals are isolated by centrifugation, washed and dryed at 40° C.
- Yield: 37.5 kg (86% of theoretical amount)
- Purity (HPLC): 99.7%

Synthesis of 6-methoxycarbonyl-2-oxindole

A solution of 13 kg propanedioic acid, [4-(methoxycarbonyl)-2-nitrophenyl]-, dimethylester (41.77 mol) in 88 L acetic acid is hydrogenated at 45° C. and under 40-50 psi in the presence of 1.3 kg Pd/C 10%. After standstill of the hydrogenation, the reaction is heated up to 115° C. for 2 hours. The catalyst is filtered off and 180 L water is added at about 50° C. The product is isolated after cooling to 5° C., centrifugation and drying at 50° C.

- Yield: 6.96 kg (87.2% of theoretical amount)
- Purity (HPLC): 99.8%

EXAMPLE 2Synthesis of the “chlorimide” (methyl-1-(chloroacetyl)-2-oxoindoline-6-carboxylate)

Method 1

6-methoxycarbonyl-2-oxindole (400 g; 2.071 mol) is suspended in toluene (1200 ml) at room temperature. Chloroacetic anhydride (540 g; 3.095 mol) is added to this suspension. The mixture is heated to reflux for 3 h, then cooled to 80° C. and methyl cyclohexane (600 ml) is added within 30 min. The resulting suspension is further cooled down to room temperature within 60 min. The mother liquor is separated and the solid is washed with ice cold methanol (400 ml). The crystals are dried to afford 515.5 g (93.5%) of the “chlorimide” compound as a white solid. ¹H-NMR (500 MHz, DMSO-d₆) δ: 8.66 (s, 1H, 6-H); 7.86 (d, J=8.3 Hz, 1H, 8-H); 7.52 (d, J=8.3 Hz, 1H, 9-H); 4.98 (s, 2H, 15-H₂); 3.95 (s, 3H, 18-H₃); 3.88 (s, 2H, 3-H₂). ¹³C-NMR (126 MHz, DMSO-d₆) δ: 174.7 (C-2); 36.0 (C-3); 131.0 (C-4); 140.8 (C-5); 115.7 (C-6); 128.9 (C-7); 126.1 (C-8); 124.6 (C-9); 166.6 (C-10); 165.8 (C-13); 46.1 (C-15); 52.3 (C-18). MS: m/z 268 (M+H)⁺. Anal. calcd. for C₁₂H₁₀ClNO₄: C, 53.85; H, 3.77; Cl, 13.25; N, 5.23. Found: C, 52.18; H, 3.64; Cl, 12.89; N, 5.00.

Method 2

6-Methoxycarbonyl-2-oxindole (10 g; 0.052 mol) is suspended in n-butyl acetate (25 ml) at room temperature. To this suspension a solution of chloroacetic anhydride (12.8 g; 0.037 mol) in n-butyl acetate (25 ml) is added within 3 min. The mixture is heated to reflux for 2 h, then cooled to 85° C. and methyl cyclohexane (20 ml) is added. The resulting suspension is further cooled down to room temperature and stirred for 2 h. The mother liquor is separated and the solid is washed with methanol (400 ml) at ambient temperature. The crystals are dried to afford 12.7 g (91.5%) of the “chlorimide” compound as a slightly yellow solid.

EXAMPLE 3Synthesis of the “chlorenol” (methyl-1-(chloroacetyl)-3-[methoxy(phenyl)methylene]-2-oxoindoline-6-carboxylate)

Method 1

Methyl-1-(chloroacetyl)-2-oxoindoline-6-carboxylate (12.0 g; 0.045 mol) is suspended in toluene (60 ml) at ambient temperature. Acetic anhydride (16.2 g; 0.157 mol) is added to this suspension. The mixture is heated to not less than 104° C. and trimethyl orthobenzoate (20.0 g; 0.108 mol) is added within 60 min. During the addition period and subsequent stirring at the same temperature for 3 h, volatile parts of the reaction mixture are distilled off. The concentration of the reaction mixture is kept constant by replacement of the distilled part by toluene (40 ml). The mixture is cooled down to 5° C., stirred for 1 h and filtrated. The solid is subsequently washed with toluene (14 ml) and with a mixture of toluene (8 ml) and ethyl acetate (8 ml). After drying, 16.3 g (91.7%) of the “chlorenol” compound are isolated as slightly yellow crystals. ¹H-NMR (500 MHz, DMSO-d₆) δ: 8.73 (d, J=1.5 Hz, 1H, 6-H); 8.09 (d, J=8.0 Hz, 1H, 9-H); 7.90 (dd, J=8.1; 1.5 Hz, 1H, 8-H); 7.61-7.48 (m, 5H, 21-H, 22-H, 23-H, 24-H, 25-H); 4.85 (s, 2H, 18-H₂); 3.89 (s, 3H, 27-H₃); 3.78 (s, 3H, 15-H₃). ¹³C-NMR (126 MHz, DMSO-d₆) δ: 165.9 (C-2+C16); 103.9 (C-3); 127.4; 128.6; 130.0; 135.4 (C-4+C-5+C-7+C-20); 115.1 (C-6); 126.1 (C-8); 122.5 (C-9); 166.7 (C-10); 173.4 (C-13); 58.4 (C-15); 46.4 (C-18); 128.6 (C-21+C-22+C-24+C-25); 130.5 (C-23); 52.2 (C-27). MS: m/z 386 (M+H)⁺. Anal. calcd. for C₂₀H₁₆ClNO₅: C, 62.27; H, 4.18; Cl, 9.19; N, 3.63. Found: C, 62.21; H, 4.03; Cl, 8.99; N, 3.52.

Method 2

Methyl-1-(chloroacetyl)-2-oxoindoline-6-carboxylate (12.0 g; 0.045 mol) is suspended in xylene (60 ml) at ambient temperature. Acetic anhydride (16.2 g; 0.157 mol) is added to this suspension. The mixture is heated to reflux, trimethyl orthobenzoate (20.0 g; 0.108 mol) is added within 40 min and heating is maintained for 4 h. The mixture is cooled down to 0° C. and the mother liquor is separated. The solid is subsequently washed with xylene (14 ml) and a mixture of xylene (8 ml) and ethyl acetate (8 ml). After drying 14.3 g (81.0%) of the “chlorenol” compound are isolated as yellow crystals.

Method 3

EXAMPLE 4Synthesis of the “enolindole” (methyl-3-[methoxy(phenyl)methylene]-2-oxoindoline-6-carboxylate)

Method 1

A solution of potassium hydroxide (0.41 g, 0.006 mol) in methanol (4 ml) is added at 63° C. to a suspension of methyl-1-(chloroacetyl)-3-[methoxy(phenyl)methylene]-2-oxoindoline-6-carboxylate (8.0 g; 0.020 mol) in methanol (32 ml). The mixture is then stirred for 30 min, cooled to 0° C. and stirring is maintained for 2 h. After filtration, the solid is washed with methanol (24 ml) and dried to afford 6.0 g (94.6%) of the “enolindole” compound as yellow crystals. ¹H-NMR (500 MHz, CDCl₃) δ: 8.08 (s, 1H, 1-H); 7.88 (d, J=7.8 Hz, 1H, 9-H); 7.75 (m, 1H, 8-H); 7.52-7.56 (m, 3H, 18-H, 19-H, 20-H); 7.40-7.45 (m, 3H, 6-H, 17-H, 21-H); 3.92 (s, 3H, 23-H₃); 3.74 (s, 3H, 13-H₃). ¹³C-NMR (126 MHz, CDCl₃) δ: 168.8 (C-2); 107.4 (C-3); 130.8 (C-4); 138.2 (C-5); 109.4 (C-6); 128.2 and 128.3 (C-7, C-16); 123.5 (C-8); 123.1 (C-9); 170.1 (C-11); 57.6 (C-13); 167.2 (C-14); 128.7 and 128.9 (C-17, C-18, C-20, C-21); 130.5 (C-19); 52.1 (C-23). MS (m/z): 310 (M+H)⁺. Anal. calcd. for C₁₈H₁₅NO₄: C, 69.89; H, 4.89; N, 4.53. Found: C, 69.34; H, 4.92; N, 4.56.

Method 2

A suspension of methyl-1-(chloroacetyl)-3-[methoxy(phenyl)methylene]-2-oxoindoline-6-carboxylate (7.0 g; 0.018 mol) in methanol (28 ml) is heated to reflux. Within 3 min, a solution of sodium methoxide in methanol (0.24 g, 30 (w/w), 0.001 mol) is added to this suspension. The mixture is then stirred for 30 min, cooled to 5° C. and stirring is maintained for 2 h. After filtration, the solid is washed with methanol (9 ml) and dried to afford 5.4 g (89.7%) of the “enolindole” compound as yellow crystals.

Method 3

A suspension of methyl-1-(chloroacetyl)-3-[methoxy(phenyl)methylene]-2-oxoindoline-6-carboxylate (8.0 g; 0.021 mol) in methanol (32 ml) is heated to reflux. A solution of sodium methoxide in methanol (0.74 g, 30% (w/w), 0.004 mol), further diluted with methanol (4 ml), is added dropwise to this suspension. The mixture is then stirred for 90 min, cooled to 0° C. and stirring is maintained for 2 h. After filtration, the solid is washed with methanol (24 ml) and dried to afford 5.9 g (91.2%) of the “enolindole” compound as yellow crystals.

EXAMPLE 5Synthesis of the “chloroacetyl” (N-(4-nitroanilino)-N-methyl-2-chloro-acetamide)

Method 1

A suspension of N-methyl-4-nitroaniline (140 g; 0.920 mol) in ethyl acetate (400 ml) is heated to 70° C. Within 90 min, chloro acetylchloride (114 g; 1.009 mol) is added to this suspension. The resulting solution is then refluxed for 1 h, cooled to 60° C. and methyl cyclohexane (245 ml) is added. The suspension is further cooled down to 0° C. and stirred for 1 h. The reaction mixture is filtrated, washed with methyl cyclohexane (285 ml) and the precipitate is dried to afford 210.4 g (92.7%) of the “chloroacetyl” compound as white crystals. ¹H-NMR (500 MHz, DMSO-d₆) δ: 8.29 (d, J=8.5 Hz, 2H, 1-H+3-H); 7.69 (d, J=8.5 Hz, 2H, 4-H+6-H); 4.35 (s, 2H, 9-H₂); 3.33 (s, 3H, 12-H₃). ¹³C-NMR (126 MHz, DMSO-d₆) δ: 124.6 (C-1+C-3); 145.6 (C-2); 127.4 (C-4+C-6); 148.6 (C-5); 165.6 (C-8); 42.7 (C-9); 37.2 (C-12). MS (m/z): 229 (M+H)⁺. Anal. calcd. for C₉H₉ClN₂O₃: C, 47.28; H, 3.97; N, 12.25. Found: C, 47.26; H, 3.99; Cl, 15.73; N, 12.29.

Method 2

A suspension of N-methyl-4-nitroaniline (20.0 g; 0.131 mol) in ethyl acetate (20 ml) is heated to 60° C. Within 15 min, a solution of chloro acetic anhydride (26.0 g; 0.151 mol) in ethyl acetate (60 ml) is added to this suspension. The resulting solution is then refluxed for 1 h, cooled to 75° C. ° C. and methyl cyclohexane (80 ml) is added. After seeding at 60° C., the suspension is further cooled down to 0° C. and stirred for 1 h. The reaction mixture is filtrated, washed with methyl cyclohexane (40 ml) and the precipitate is dried to afford 25.9 g (83.3%) of the “chloroacetyl” compound as grey crystals.

EXAMPLE 6Synthesis of the “nitroaniline” (N-(4-nitrophenyl)-N-methyl-2-(4-methylpiperazin-1-yl)acetamide) and of the “aniline” (N-(4-aminophenyl)-N-methyl-2-(4-methylpiperazin-1-yl)acetamide)

Method 1

A suspension of N-(4-nitroanilino)-N-methyl-2-chloro-acetamide (20.0 g; 0.087 mol) in toluene (110 ml) is heated to 40° C. Within 30 min, 1-methylpiperazine (21.9 g; 0.216 mol) is added dropwise. After purging of the dropping funnel with toluene (5 ml) the reaction mixture is stirred for 2 h at 55° C., cooled to ambient temperature and washed with water (15 ml). The organic layer is diluted with isopropanol (100 ml) and Pd/C (10%; 1.0 g) is added. After subsequent hydrogenation (H₂, 4 bar) at 20° C. the catalyst is removed. Approximately ⅘ of the volume of the resulting solution is evaporated at 50° C. The remaining residue is dissolved in ethyl acetate (20 ml) and toluene (147 ml) heated to 80° C., then cooled to 55° C. and seeded. The reaction mixture is further cooled to 0° C. and stirred for 3 h at the same temperature. After filtration, the solid is washed with ice cold toluene (40 ml) and dried to afford 20.2 g (88.0%) of the “aniline” compound as white crystals. ¹H-NMR (500 MHz, DMSO-d₆) δ: 6.90 (d, J=8.5 Hz, 2H, 4-H+6-H); 6.65 (d, J=8.5 Hz, 2H, 1-H+3-H); 5.22 (2H, 19-H₂); 3.04 (s, 3H, 9-H₃); 2.79 (s, 2H, 11-H₂); 2.32 (m, 4H, 13-H₂+17-H₂); 2.23 (m, 4H, 14-H₂+16-H₂); 2.10 (s, 3H, 18-H₃). ¹³C-NMR (126 MHz, DMSO-d₆) δ: 114.0 (C-1+C-3); 148.0 (C-2); 127.6 (C-4+C-6); 131.5 (C-5); 168.9 (C-8); 36.9 (C-9); 58.5 (C-11); 52.4 (C-13+C-17); 54.6 (C-14+C-16); 45.7 (C-18). MS (m/z): 263 (M+H)⁺. Anal. calcd. for C₁₄H₂₂N₄O: C, 64.09; H, 8.45; N, 21.36. Found: C, 64.05; H, 8.43; N, 21.39.

Method 2

A suspension of N-(4-nitroanilino)-N-methyl-2-chloro-acetamide (14.5 g; 0.063 mol) in ethyl acetate (65 ml) is heated to 40° C. Within 30 min, 1-methylpiperazine (15.8 g; 0.156 mol) is added dropwise. After purging of the dropping funnel with ethyl acetate (7 ml) the reaction mixture is stirred at 50° C. for 90 min, cooled to ambient temperature and washed with water (7 ml). The organic layer is diluted with isopropanol (75 ml) and dried over sodium sulphate. After separation of the solid, Pd/C (10%; 2.0 g) is added and the solution is hydrogenated (H₂, 5 bar) at ambient temperature without cooling. Subsequently the catalyst is removed by filtration and the solvent is evaporated at 60° C. The remaining residue is dissolved in ethyl acetate (250 ml) and recrystallized. After filtration and drying 10.4 g (60.4%) of the “aniline” compound are isolated as white crystals.

EXAMPLE 7Synthesis of the “anilino” (3-Z-[1-(4-(N-((4-methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone)

Method 1

A suspension of methyl-3-[methoxy(phenyl)methylene]-2-oxoindoline-6-carboxylate (10.0 g; 0.032 mol) and N-(4-aminophenyl)-N-methyl-2-(4-methylpiperazin-1-yl)acetamide (8.6 g; 0.032 mol) in a mixture of methanol (72 ml) and N,N-dimethylformamide (18 ml) is heated to reflux. After 7 h of refluxing the suspension is cooled down to 0° C. and stirring is maintained for additional 2 h. The solid is filtered, washed with methanol (40 ml) and dried to afford 15.4 g (88.1%) of the “anilino” compound as yellow crystals. ¹H-NMR (500 MHz, DMSO-d₆) δ: 11.00 (s, 1H, 23-H); 12.23 (s, 19-H); 7.61 (t; J=7.1 Hz, 1H, 33-H); 7.57 (t, J=7.5 Hz, 2H, 32-H+34-H); 7.50 (d, J=7.7 Hz, 2H, 31-H+35-H); 7.43 (d, J=1.6 Hz, 1H, 29-H); 7.20 (dd, J=8.3; 1.6 Hz, 1H, 27-H); 7.13 (d, J=8.3 Hz, 2H, 14-H+18-H); 6.89 (d, 8.3 Hz, 2H, 15-H+17-H); 5.84 (d, J=8.3 Hz, 1H, 26-H); 3.77 (s, 3H, 40-H₃); 3.06 (m, 3H, 12-H₃); 2.70 (m, 2 H, 8-H₂); 2.19 (m, 8H, 2-H₂, 3-H₂, 5-H₂, 6-H₂); 2.11 (s, 3H, 7-H₃). ¹³C-NMR (126 MHz, DMSO-d₆) δ: 54.5 (C-2+C-6); 52.2 (C-3+C-5); 45.6 (C-7); 59.1 (C-8); 168.5 (C-9); 36.6 (C-12); 140.1 (C-13); 127.6 (C-14+C-18); 123.8 (C-17+C-15); 137.0 (C-16); 158.3 (C-20); 97.5 (C-21); 170.1 (C-22); 136.2 (C-24); 128.9 (C-25); 117.2 (C-26); 121.4 (C-27); 124.0 (C-28); 109.4 (C-29); 131.9 (C-30); 128.4 (C-31+C-35); 129.4 (C-32+C-34); 130.4 (C-33); 166.3 (C-37); 51.7 (C-40). MS (m/z): 540 (M+H)⁺. Anal. calcd. for C₃₁H₃₃N₅O₄: C, 69.00; H, 6.16; N, 12.98. Found: C, 68.05; H, 6.21; N, 12.81.

Method 2

A suspension of methyl-3-[methoxy(phenyl)methylene]-2-oxoindoline-6-carboxylate (20.0 g; 0.064 mol) and N-(4-aminophenyl)-N-methyl-2-(4-methylpiperazin-1-yl)acetamide (17.1 g; 0.065 mol) in methanol (180 ml) is heated to reflux for 7.5 h. The resulting suspension is cooled down to 10° C. within 1 h and stirring is maintained for 1 h. After filtration, the solid is washed with ice cold methanol (80 ml) and dried to afford 31.0 g (89.0%) of the “anilino” compound as yellow crystals.

EXAMPLE 8Synthesis of the 3-Z-[1-(4-(N-((4-methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone, monoethanesulfonate

A suspension of 3-Z-[1-(4-(N-((4-methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone (30.0 g; 0.055 mol) in methanol (200 ml) and water (2.4 ml) is heated to 60° C. Aqueous ethanesulfonic acid (70% (w/w); 8.75 g; 0.056 mol) is added to the reaction mixture. The resulting solution is cooled to 50° C., seeded and then diluted with isopropanol (200 ml). The mixture is further cooled to 0° C. and stirred for 2 h at this temperature. The precipitate is isolated, washed with isopropanol (120 ml) and dried to furnish 35.1 g (97.3%) of the monoethanesulfonate salt of the compound as yellow crystals. ¹H-NMR (400 MHz, DMSO-d₆) δ: 12.26 (s, 11-H); 10.79 (s, 1H, 1-H); 9.44 (s, 1H, 24-H); 7.64 (m, 1H, 32-H); 7.59 (m, 2H, 31-H+33-H); 7.52 (m, 2H, 30-H+34-H); 7.45 (d, J=1.6 Hz, 1H, 7-H); 7.20 (dd, J=8.2; 1.6 Hz, 1H, 5-H); 7.16 (m, 2H, 14-H+16-H); 6.90 (m, 2H, 13-H+17-H); 5.85 (d, J=8.2 Hz, 1H, 4-H); 3.78 (s, 3H, 37-H₃); 3.45-2.80 (broad m, 4H, 23-H₂+25-H₂); 3.08 (s, 3H, 28-H₃); 2.88 (s, 2H, 20-H₂); 2.85-2.30 (broad m, 4H, 22-H₂+26-H₂); 2.75 (s, 3H, 27-H₃); 2.44 (q, J=7.4 Hz, 2H, 39-H₂); 1.09 (t, J=7.4 Hz, 3H, 38-H₃). ¹³C-NMR (126 MHz, DMSO-d₆) δ: 9.8 (C-38); 36.6 (C-28); 42.3 (C-27); 45.1 (C-39); 51.7 (C-37); 48.9 (C-22+C-26); 52.6 (C-23+C-25); 57.5 (C-20); 97.7 (C-3); 109.5 (C-7); 117.3 (C-4); 121.4 (C-5); 123.8 (C-13+C-17); 124.1 (C-6); 127.7 (C-14+C-16); 128.4 (C-30+C-34); 128.8 (C-9); 129.5 (C-31+C-33); 130.5 (C-32); 132.0 (C-29); 168.5 (C-9); 136.3 (C-8); 137.3 (C-12); 139.5 (C-15); 158.1 (C-10); 166.3 (C-35); 168.0 (C-19); 170.1 (C-2). MS (m/z): 540 (M_(base)+H)⁺. Anal. calcd. for C₃₃H₃₉N₅O₇S: C, 60.17; H, 6.12; N, 10.63; S, 4.87. Found: C, 60.40; H, 6.15; N, 10.70; S, 4.84.

CLIPS

After a classical malonic ester addition to arene 3, the resulting nitro benzene (4) is hydrogenated under acidic conditions, furnishing the 6-methoxycarbonyl-substituted oxindole 5 via decarboxylative cyclization. Condensation of 5 with trimethyl orthobenzoate in acetic anhydride leads to compound 6, one of the two key building blocks of the synthesis. The concomitant N-acetylation of the oxindole activates the scaffold for the condensation reaction.

The aniline side chain (9) can be prepared by a one-pot bromo-acetylation/amination of the para-nitro-phenylamine (7) using bromoacetyl bromide and N-methylpiperazine and a subsequent hydrogenation furnishing 9 as the second key building block. Condensation of both building blocks in an addition–elimination sequence and subsequent acetyl removal with piperidine furnishes 2 as free base (pK_a = 7.9), which subsequently is converted into its monoethanesulfonate salt (1). Compound 1 is highly crystalline (mp = 305 °C) and exhibits a log P of 3.0 and good aqueous solubility (>20 mg/mL in water).

CLIPS

see

http://www.yaopha.com/2014/07/09/synthesis-of-vargatef-nintedanib-boehringer-ingelheim-idiopathic-pulmonary-fibrosis-drug/

NINTEDANIB SINA

CLICK ON PIC

Updates………..

“J.Med.Chem” 2009 Vol. 52, page 4466-4480 and the “Chinese Journal of Pharmaceuticals” 2012, Vol. 43, No. 9, page 726-729 reported a further intermediate A and B synthesis, and optimized from the reaction conditions, the reaction sequence, the feed ratio and catalyst selection, etc., so that the above-described synthetic routes can be simplified and reasonable.

PATENT

CN105461609A

NINTE PIC

MACHINE TRANSLATED FROM CHINESE

Synthesis of Trinidad Neeb (I),

A 500ml reaction flask was charged 30g of compound V, 22.5g compound of the VI, ethanol 300ml, sodium bicarbonate and 15g, the reaction was heated to reflux for 2 hours, the reaction mixture was added to 600ml of water, there are large amount of solid precipitated, was filtered, the cake washed with 100ml washed once with methanol, a yellow solid 41.9g refined Trinidad Neeb (I). Yield 92.7%.

4 bandit R (400MHz, dmso) δ11 · 97 (s, 1H), 8.38 (s, 1H), 7.97 (dd, J = 11.9, 5.0Hz, 2H), 7.67 (d, J = 8.1Hz, 1H), 7.16 (ddd, J = 26.9, 22.1, 7.0Hz, 5H), 6.85 (d, J = 8.6Hz, 2H), 6.63 (d, J = 8.7Hz, 2H), 3.90 (s, 3H), 2.99 (s, 3H), 2.69 (s, 2H), 2.51-2.24 (m, 8H), 2.20 (s, 3H) MS:. m / z540 (m + 1) + 2 Example: Preparation of compound IV 250ml reaction flask was added 28.7g of 2- oxindole-6-carboxylate, 130ml ethanol, stirred open, then added 30.3ml (31.8g) benzaldehyde, 2.97 mL piperidine was heated to 70 ° C-80 after ° C for 2 hours, allowed to cool to 20 ° C- 30 ° C, the precipitate was filtered, the filter cake was washed with absolute ethanol, 50 ° C 5 hours and dried in vacuo give a yellow solid 38.7g (IV of), yield: 92.4% Preparation of compound V square in 500ml reaction flask was added 30g compound IV, dichloromethane 360ml, cooled with ice water to 0-5 ° C, 71/92 bromine 3.lml (9.7g), drop finished warmed to 20- 30 ° C, 3 hours after the reaction, the reaction solution was washed once with 150ml dichloromethane layer was concentrated oil was done by adding 200ml ethanol crystallization, filtration, 60 ° C and dried under vacuum 36.lg white solid (V ), yield: 93 · 8%.

After Trinidad Technip (I) are synthesized in the reaction flask was added 500ml of 30g compound V, 33.0g compound of the VI, ethanol 300ml, sodium bicarbonate, 15g, was heated to reflux for 2 hours, the reaction mixture was added to 600ml water, there are large amount of solid precipitated, was filtered, the filter cake washed once with 100ml methanol obtained 42.3g of yellow solid was purified by Technip Trinidad (I). Yield 93.6%.

ΧΗNMR (400MHz, dmso) δ11.94 (s, 1Η), 8.36 (s, 1H), 7.96 (dd, J = 11.9, 5.0Hz, 2H), 7.67 (d, J = 8.1Hz, 1H) , 7.16 (ddd, J = 26.9, 22.1, 7.0Hz, 5H), 6.85 (d, J = 8.6Hz, 2H), 6.61 (d, J = 8.7Hz, 2H), 3.90 (s, 3H), 2.99 ( s, 3H), 2.65 (s, 2H), 2.50-2.30 (m, 8H), 2.20 (s, 3H) MS:. m / z540 (m + 1) + square

PATENT

WO2016037514

(I) 2.30g, yield 85.3%. Melting point 241 ~ 243 ℃, Mass spectrum (the EI): m / Z 540 (the M + the H), ¹ the H NMR (of DMSO D _{. 6} ): 2.27 (S, 3H), 2.43 (m, 8H), 2.78 (S, 2H) , 3.15 (s, 3H), 3.82 (s, 3H), 5.97 (d, J = 8.3Hz, 1H), 6.77 (d, J = 8.7Hz, 1H), 6.96 (d, J = 8.6Hz, 2H) , 7.32-7.62 (m, 8H), 8.15 (s, 1H), 12.15 (s, 1H).

CLIPS

http://pubs.rsc.org/en/content/articlelanding/2015/ay/c5ay01207d#!divAbstract

Nintedanib
Systematic (IUPAC) name
Nintedanib
Methyl (3Z)-3-{[(4-{methyl[(4-methylpiperazin-1-yl)acetyl]amino}phenyl)amino](phenyl)methylidene}-2-oxo-2,3-dihydro-1H-indole-6-carboxylate
Clinical data
Trade names	Vargatef, Ofev
AHFS/Drugs.com	Consumer Drug Information
Pregnancy cat.	US: D
Legal status	US: ℞-only
Routes	Oral and intravenous
Identifiers
CAS number	656247-17-5
ATC code	None



Chemical data
Formula	C₃₁H₃₃N₅O₄
Mol. mass	539.6248 g/mol

References

Hilberg, F.; G. J. Roth, M. Krssak, S. Kautschitsch, W. Sommergruber, U. Tontsch-Grunt, P. Garin-Chesa, G. Bader, A. Zoephel, J. Quant, A. Heckel, W. J. Rettig (2008). “BIBF 1120: triple angiokinase inhibitor with sustained receptor blockade and good antitumor efficacy”. Cancer Res 68 (12): 4774–82. doi:10.1158/0008-5472.CAN-07-6307. ISSN 1538-7445. PMID 18559524.
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Merten, J.; et. al. Process for the manufacture of an indolinone derivative. US20110201812A1
2. Roth, G. J.; et. al. 3-z-[1-(4-(n-((4-methyl-piperazin-1-yl)-methylcarbonyl)-n-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone-monoethanesulphonate and the use thereof as a pharmaceutical composition. WO2004013099A1
3. Roth, G. J.; et. al. Design, Synthesis, and Evaluation of Indolinones as Triple Angiokinase Inhibitors and the Discovery of a Highly Specific 6-Methoxycarbonyl-Substituted Indolinone (BIBF 1120). J Med Chem, 2009, 52(14), 4466-4480.

ニンテダニブエタンスルホン酸塩
Nintedanib Ethanesulfonate

C31H33N5O4.C2H6O3S : 649.76
[656247-18-6]

US7119093 *	Jul 21, 2003	Oct 10, 2006	Boehringer Ingelheim Pharma Gmbh & Co. Kg	3-Z-[1-(4-(N-((4-Methyl-piperazin-1-yl)-methylcarbonyl)-N-methyl-amino)-anilino)-1-phenyl-methylene]-6-methoxycarbonyl-2-indolinone-monoethanesulphonate and the use thereof as a pharmaceutical composition

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