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Specific Stereoisomeric Conformations Determine the Drug Potency of Cladosporin Scaffold against Malarial Parasite

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May 272018
 

 

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Specific Stereoisomeric Conformations Determine the Drug Potency of Cladosporin Scaffold against Malarial Parasite

https://pubs.acs.org/doi/abs/10.1021/acs.jmedchem.8b00565

Pronay Das†ab, Palak Babbar†c, Nipun Malhotra†c, Manmohan Sharmac , Goraknath R. Jachakab , Rajesh G. Gonnadebd, Dhanasekaran Shanmugambe, Karl Harlosf , Manickam Yogavelc , Amit Sharmac *, and D. Srinivasa Reddyab* †All three have contributed equally to this work.
aOrganic Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
b Academy of Scientific and Innovative Research (AcSIR), New Delhi 110025, India
cMolecular Medicine Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi 110067, India dCenter for Material Characterization, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
e Biochemical Sciences Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
fDivision of Structural Biology, Welcome Trust Centre for Human Genetics, The Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, UK
J. Med. Chem., Just Accepted Manuscript
DOI: 10.1021/acs.jmedchem.8b00565
Publication Date (Web): May 21, 2018
Copyright © 2018 American Chemical Society
The dependence of drug potency on diastereomeric configurations is a key facet. Using a novel general divergent synthetic route for a three-chiral centre anti-malarial natural product cladosporin, we built its complete library of stereoisomers (cladologs) and assessed their inhibitory potential using parasite-, enzyme- and structure-based assays.
We show that potency is manifest via tetrahyropyran ring conformations that are housed in the ribose binding pocket of parasite lysyl tRNA synthetase (KRS). Strikingly, drug potency between top and worst enantiomers varied 500-fold, and structures of KRS-cladolog complexes reveal that alterations at C3 and C10 are detrimental to drug potency where changes at C3 are sensed by rotameric flipping of Glutamate332.
Given that scores of anti-malarial and anti-infective drugs contain chiral centers, this work provides a new foundation for focusing on inhibitor stereochemistry as a facet of anti-microbial drug development.
Cladosporin (12) displays exquisite selectivity for the parasite lysyl-tRNA synthetase over human enzyme. This species specific selectivity of cladosporin has been previously described through comprehensive sequence alignment, where the residues val329 and ser346 seem to be sterically crucial for accommodating the methyl moiety of THP ring10. The structural features of compound 12 clearly indicate the presence of three stereocenters, and therefore 2n (n=3) i.e., eight stereoisomers are possible (Fig.1). Till date, only one asymmetric total synthesis of cladosporin13 has been achieved which was followed by another report of formal syntheses14. Here, we have developed a general chemical synthesis route to synthetically access all the eight possible stereoisomers of compound 12.
cladosporin (compound 12) (0.052 g) as a white solid with a yield of 54 %. Melting point: 171-173 °C; [α]25 D = -15.75 (c = 0.6, EtOH); IR υmax(film): cm-1 3416, 3022, 1656, 1218; 1H NMR (400 MHz, CDCl3): δ 11.06 (s, 1H), 7.47 (br. s., 1H), 6.29 (s, 1H), 6.16 (s, 1H), 4.68 (t, J = 9.8 Hz, 1H), 4.12 (s, 1H), 4.01 (s, 1H), 2.89 – 2.75 (m, 2H), 2.00 – 1.94 (m, 1H), 1.87 – 1.81 (m, 1H), 1.70 – 1.63 (m, 4H), 1.35 (d, J = 6.1 Hz, 2H), 1.23 (d, J = 6.7 Hz, 3H); 13C NMR (100 MHz, CDCl3): δ 169.9, 164.3, 163.1, 141.8, 106.7, 102.0, 101.5, 76.3, 68.0, 66.6, 39.3, 33.6, 30.9, 18.9, 18.1; HRMS calculated for C16H21O5 [M + H]+ 293.1384, observed 293.1379.
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Dr. D. Srinivasa Reddy has been appointed as an editor of Bioorganic & Medicinl Chemistry Letters, Elsevier Publications. Congratulation Sir !

Click here for details. https://www.journals.elsevier.com/bioorganic-and-medicinal-chemistry-letters

The research interests of his group lie in issues related to application of oriented organic synthesis, in particular total synthesis of biologically active natural products, medicinal chemistry and crop protection. This team has been credited with having accomplished total synthesis of more than 25 natural products with impressive biological activities. “Some of our recent achievements include identification of potential leads, like antibiotic compound based on hunanamycin natural product for treating food infections, anti-diabetic molecule in collaboration with an industry partner and  anti-TB compound using a strategy called ‘re-purposing of a drug scaffold’,” said Reddy.

A total of two awardees out of four were from CSIR institutes. In addition to Reddy, Rajan Shankarnarayanan, CSIR – CCMB, Hyderabad (basic sciences), also was conferred with the award. Vikram Mathews, CMC, Vellore (medical research) and Prof Ashish Suri, AIIMS, New Delhi (clinical research), were the others to receive the awards.

With more than 80 scientific publications and 35 patents, Reddy is one of the most prominent scientists in the city and has already been honoured with the Shanti Swarup Bhatnagar prize in chemical sciences. Reddy is also a nominated member of the scientific body of Indian Pharmacopoeia, government of India and was  elected as a fellow of the Telangana and Maharashtra Academies of Sciences in addition to the National Academy of Sciences, India (NASI).

//////////CLADOSPORIN, NCL, CSIR, SRINIVASA REDDY, PUNE, MALARIA
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Dr D. Srinivasa Reddy of CSIR NCL wins the OPPI Scientist Award 2017 for his work in organic chemistry.

 award  Comments Off on Dr D. Srinivasa Reddy of CSIR NCL wins the OPPI Scientist Award 2017 for his work in organic chemistry.
Oct 142017
 

Dr D. Srinivasa Reddy of CSIR NCL @CSIR_IND wins the OPPI Scientist Award 2017 for his work in organic chemistry.

At TAJ LAND ENDS MUMBAI, INDIA

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WO 2016181414, IVACAFTOR, NEW PATENT, COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH

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Nov 242016
 

Image result for COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCHImage result for REDDY SRINIVASA DUMBALAImage result for INDIA ANIMATED FLAG

CSIR, Dr. D. Srinivasa Reddy

WO2016181414, PROCESS FOR THE SYNTHESIS OF IVACAFTOR AND RELATED COMPOUNDS

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2016181414&recNum=1&maxRec=&office=&prevFilter=&sortOption=&queryString=&tab=PCTDescription

REDDY, Dumbala Srinivasa; (IN).
NATARAJAN, Vasudevan; (IN).
JACHAK, Gorakhnath Rajaram; (IN)

COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH [IN/IN]; Anusandhan Bhawan, Rafi Marg New Delhi 110001 (IN)

The present patent discloses a novel one pot two-step process for the synthesis of ivacaftor and related compounds of [Formula (I)], wherein R1, R2, R3, R4, R5, R6, R7 and Ar1are as described above; its tautomers or pharmaceutically acceptable salts thereof starting from indole acetic acid amides

See Eur J Org Chem, Nov 2015, for an article by the inventors, describing a process for preparing ivacaftor using 4-quinolone-3-carboxylic acid amides. The inventors appear to be based at National Chemical Laboratories of CSIR.

Ivacaftor, also known as N-(2,4-di-tert-butyl-5-hydroxyphenyl)-l,4-dihydro-4-oxoquinoline-3-carboxamide, having the following Formula (A):

Formula (A)

[003] Ivacaftor was approved by FDA and marketed by vertex pharma for the treatment of cystic fibrosis under the brand name KALYDECO® in the form of 150 mg oral tablets. Kalydeco® is indicated for the treatment of cystic fibrosis in patients age 6 years and older who have a G55ID mutation in the CFTR (cystic fibrosis transmembrane conductance regulator)gene.

[004] U.S. 20100267768 discloses a process for preparation of ivacaftor, which involves the coupling of 4-oxo-l,4-dihydro-3- quinoline carboxylic acid with hydroxyl protected phenol intermediate in the presence of propyl phosphonic anhydride (T3P®) followed by deprotection of hydroxyl protection group and optional crystallization with isopropyl acetate. The publication also discloses the use of highly expensive coupling reagent, propyl phosphonic anhydride; which in turn results to an increase in the manufacturing cost. The process disclosed is schematically represented as follows:

[005] Article titled “Discovery of N-(2,4-Di-te -butyl-5-hydroxyphenyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide (VX-770, Ivacaftor), a Potent and Orally Bioavailable CFTR Potentiator” byHadida,S et. al in . Med. Chem., 2014, 57 (23), pp 9776-9795 reportsN-(2,4-di-teri-butyl-5-hydroxyphenyl)-4-oxo- 1 ,4-dihydroquinoline-3-carboxamide (VX-770, 48, ivacaftor), an investigational drug candidate approved by the FDA for the treatment of CF patients 6 years of age and older carrying the G551D mutation.

[006] WO 2014125506 A2 discloses a process for the preparation of ivacaftor in high yield and purity by using novel protected quinolone carboxylic acid compounds as intermediates.

[007] Article titled “Expeditious synthesis of ivacaftor” by Jingshan Shen et. al in Heterocycles, 2014, 89 (4), pp 1035 – 1040 reports an expeditious synthesis for ivacaftor featuring modified Leimgruber-Batcho procedure. The overall yield is 39% over six steps from commercially available 2-nitrobenzoyl chloride.

[008] U.S.2011/064811 discloses a process for preparation of ivacaftor, which involves condensation of 4-oxo-l,4-dihydro-3- quinolone carboxylic acid with 5- amino-2,4-di-(tert-butyl)phenol in the presence of HBTU followed by the formation of ethanol crystalate, which is then treated with diethyl ether to yield ivacaftor as a solid.

[010] U.S. 7,495,103 discloses modulators of ATP-binding cassette transporters such as ivacaftor and a process for the preparation of modulators of ATP-binding cassette transporters such as quinolone compounds. The process includes condensation of 4-oxo-l,4-dihydro-3 -quinolone carboxylic acid with aniline in presence of 2-(lH-7-azabenzotriazol-l-yl)-l,l,3,3-tetramethyluronium hexafluoro phosphate methanaminium (HATU) as shown:

[011] U.S. 2011/230519 discloses a process for preparation of 4-oxo-l,4-dihydro-3-quinoline carboxylic acid by reaction of aniline with diethylethoxymethylenemalonate at 100-110°C followed by cyclization in phenyl ether at temperature 228-232°C and then hydrolysis, as shown below:

[012] US 7,402,674 B2 discloses 7-Phenylamino-4-quinolone-3-carboxylic acid derivatives, process for their preparation and their use as medicaments.

[013] US 4,981,854 discloses l-aryl-4-quinolone-3 carboxylic acids, processes for their preparation and anti-bacterial agents and feed additives containing these compounds.

Article titled “Ozonolysis Applications in Drug Synthesis” by Van Ornum,S.G. ; Champeau,R.M.; Pariza,R. in Chem. Rev., 2006, 106 (7), pp 2990-3001 reports that ozonolysis for the synthesis of numerous interesting bioactive natural products and pharmaceutical agents.

[014] Article titled “Safe Execution of a Large-Scale Ozonolysis: Preparation of the Bisulfite Adduct of 2-Hydroxyindan-2-carbox-aldehyde and Its Utility in a Reductive Animation” by RaganJ.A. et. al. in Org. Proc. Res. Dev., 2003, 7 (2), pp 155-160 reports various routes to bisulfite adduct, the most efficient of which involved vinyl Grignard addition to 2-indanone followed by ozonolysis and workup with aqueous NaHS03 to effect reduction and bisulfite formation in a single pot. The utility of bisulfite adduct is as an aldehyde surrogate in a reductive amination reaction.

[015] The reported methods for the synthesis of ivacaftor suffered from several drawbacks such as harsh conditions, high temperature reactions and use of large excess of polyphosphoric acid and corrosive phosphoryl chloride etc. Furthermore, synthesis of ivacaftor requires use of high performance liquid chromatography (HPLC) techniques for the separation of ivacaftor and their analogues.

[016] Therefore, development of a simple and efficient synthetic route is in urgent need. Accordingly the present inventors developed environmentally benign, cost effective and short synthetic route for the synthesis of ivacaftor and their analogues.

Example 1:

Procedur A:

To a solution of indole acetic acid (500 mg, 2.85 mmol), aniline (2.85 mmol), HOBt (3.4 mmol) in acetonitrile (10 mL), EDC.HCl (3.4 mmol) followed by DIPEA (11.4 mmol) was added, and mixture was stirred for 16 h at ambient temperature. The

reaction mixture was evaporated to dryness, diluted with EtOAc (25 mL), washed with saturated aqueous NaHC03 solution (5 mL), H20 (5 mL), brine (5 mL), and dried over Na2S04. The crude material obtained after removal of solvent was purified by column chromatography (silica gel 230-400 mesh, ethyl acetate – pet ether) to afford corresponding amide as a colorless solid.

[040] Example 2:

2-(lH-indol-3-yl)-N-phenylacetamide (1) :

Yield: 570 mg; 80%; 1H NMR (200MHz, DMSO-d6) δ = 10.95 (brs, 1 H), 10.14 (s, 1 H), 7.64 (d, J = 7.8 Hz, 3 H), 7.47 – 7.24 (m, 4 H), 7.21 – 6.92 (m, 3 H), 3.76 (s, 2H); MS: 273 (M+Na)+.

[041] Example 3:

5-(2-(lH-indol-3-yl)acetamido)-2,4-di-tert-butylphenyl methyl carbonate (2): Yield: 800 mg; 64%; 1H NMR (200 MHz, DMSO-d6) δ = 11.51 (brs, 1 H), 9.41 (s, 1 H), 8.12 (d, J = 7.6 Hz, 1 H), 7.96 – 7.78 (m, 3 H), 7.71 – 7.42 (m, 3 H), 4.34 (s, 3 H), 4.30 (s, 2 H), 1.79 (s, 9 H), 1.64 (s, 9 H); MS: 459 (M+Na)+.

[042] Example 4:

(S)-2-(lH-indol-3-yl)-N-(l-phenylethyl)acetamide (3):

Yield: 620 mg; 78%; 1H NMR (400MHz ,DMSO-d6)5 = 10.88 (brs, 1 H), 8.48 (d, J = 8.1 Hz, 1 H), 7.59 (d, J = 7.8 Hz, 1 H), 7.39 – 7.26 (m, 5 H), 7.25 – 7.16 (m, 2 H), 7.08 (t, J = 7.3 Hz, 1 H), 7.02 – 6.95 (m, 1 H), 4.96 (t, J = 7.3 Hz, 1 H), 3.59 (s, 2H), 1.38 (d, J = 7.1 Hz, 3 H).

[043] Example 5:

N-(4-Fluorophenyl)-2-(lH-indol-3-yl)acetamide (4):

1H NMR (400 MHz, DMSO-d6) : δ 10.93 (brs, 1H), 10.17 (s, 1H), 7.68 – 7.61 (m, 3H), 7.36 (d, J= 8.1 Hz, 1H), 7.27 (d, J= 2.0 Hz, 1H), 7.15 – 7.13 (m, 3H), 7.11 – 6.99 (m, 1H), 3.73 (s, 2H); 13C NMR (100 MHz, DMSO-d6) : δ 170.1, 159.5, 157.1, 136.6, 136.3, 127.7, 124.4, 121.5, 121.3, 121.2, 119.1, 118.9, 115.8, 115.6, 111.8, 108.9, 34.2; MS: 269 (M+H)+

[044] Example 6:

N-(4-Chlorophenyl)-2-(lH-indol-3-yl)acetamide (5):

1H NMR (200 MHz, DMSO-d6): 510.93 (brs, 1H),10.24 (s, 1H), 7.67 – 7.59 (m, 3H), 7.36 – 7.27 (m, 4H), 7.12 – 6.98 (m, 2H), 3.74 (s, 2H); 13CNMR (100 MHz, DMSO-d6): 5170.4, 138.9, 136.7, 129.1, 127.8, 127.1, 124.5, 121.6, 121.2, 119.2, 119.0, 115.7, 111.9, 108.9, 34.3; MS: 285 (M+H)+.

[045] Example 7:

2-(lH-Indol-3-yl)-N-(p-tolyl)acetamide (6) :

1H NMR (400 MHz, DMSO-d6): 510.91 (brs, 1H), 10.01 (s, 1H), 7.62 (d, J= 7.8 Hz, 1H), 7.50 (d, J= 8.6 Hz, 2H), 7.37 (d, J= 8.1 Hz, 1H), 7.29 – 7.26 (m, 1H), 7.10 – 7.07 (m, 3H), 7.01 – 6.99 (m, 1H), 3.71 (s, 2H), 2.23 (s, 3H); 13C NMR (100 MHz, DMSO-de): 5170.0, 137.4, 136.6, 132.4, 129.5, 127.7, 124.3, 121.4, 119.6, 119.2, 118.8, 111.8, 109.1, 34.2, 20.9; MS: 265 (M+H)+.

[046] Example 8:

N-(4-Ethylphenyl)-2-(lH-indol-3-yl)acetamide (7):

XH NMR (400 MHz, DMSO-d6): 510.91 (brs, 1H), 10.01 (s, 1H), 7.61 (s, 1H), 7.52 (d, J= 8.3 Hz, 2H), 7.36 (d, J= 8.1 Hz, 1H), 7.26 (s, 1H), 7.15 – 7.04 (m, 3H), 6.99 (s, 1H), 2.55 (t, J= 7.5 Hz, 2H), 1.15 (t, J= 7.5 Hz, 3H); 13C NMR (100 MHz, DMSO-d6): 5169.9, 138.9, 137.6, 136.6, 128.3, 127.7, 124.3, 121.4, 119.6, 119.2, 118.8, 111.8, 109.1, 40.6, 40.4, 40.2, 40.0, 39.8, 39.6, 39.4, 34.2, 28.0, 16.2; MS: 279 (M+H)+.

[047] Example 9:

2-(lH-Indol-3-yl)-N-(4-propylphenyl)acetamide (8):

1H NMR (400 MHz, DMSO-d6): 58.48 (brs, 1H), 7.64 (d, J = 8.1 Hz, 1H), 7.50 – 7.42 (m, 2H), 7.33 – 7.15 (m, 6H), 7.07 (d, J= 8.3 Hz, 2H), 3.92 (s, 2H), 2.52 (t, J= 7.6 Hz, 2H), 1.65 – 1.53 (m, 2H), 0.91 (t, J= 7.3 Hz, 3H); 13C NMR (100 MHz, DMSO-d6): 5169.7, 138.9, 136.5, 135.2, 128.8, 126.9, 124.0, 122.8, 120.4, 120.1, 118.7, 111.6, 108.7, 37.4, 34.5, 24.6, 13.7; MS: 315 (M+Na)+.

[048] Example 10:

2-(lH-Indol-3-yl)-N-(4-isopropylphenyl)acetamide (9) :

yield 79% ; 1H NMR (400 MHz, DMSO-d6): δ 10.91 (brs, 1H), 10.01 (s, 1H), 7.62 (d, = 7.8 Hz, 1H), 7.55 – 7.49 (m, = 8.6 Hz, 2H), 7.37 (d, = 8.1 Hz, 1H), 7.26 (d, = 2.0 Hz, 1H), 7.18 – 7.11 (m, = 8.6 Hz, 2H), 7.11 – 7.05 (m, 1H), 7.02 – 6.95 (m, 1H), 2.95 – 2.71 (m, 1H), 1.17 (d, = 6.8 Hz, 6H); 13C NMR (100 MHz, DMSO-d6): δ 169.9, 143.5, 137.6, 136.6, 127.7, 126.8, 124.3, 121.4, 119.7, 119.2, 118.8, 111.8, 109.2, 24.4; MS: 315 (M+Na)+.

[049] Example 11:

2-(lH-indol-3-yl)-N-(4-(trifluoromethoxy)phenyl)acetamide (10):

Yield 85% ; 1H NMR (400 MHz, CDC13): δ 8.35 (brs., 1 H), 7.44 – 7.38 (m, 2 H), 7.27 – 7.21 (m, 3 H), 7.12 – 7.05 (m, 1H), 7.03 – 6.95 (m, 2H), 6.93 (d, = 8.6 Hz, 2H), 3.75 (s, 2H); 13C NMR (100 MHz, CDC13): δ 170.0, 145.3, 136.5, 136.2, 126.8, 124.1, 123.0, 121.6, 121.2, 120.5, 118.5, 111.7, 108.2, 34.4; MS: 335 (M+Na)+.

[050] Example 12:

N-(2-chloro-5-methoxyphenyl)-2-(lH-indol-3-yl)acetamide (11):

Yield 75% ; XH NMR (200 MHz, DMSO-d6): δ 10.98 (brs, 1H), 9.27 (s, 1H), 7.59 (d, = 7.8 Hz, 1H), 7.53 (d, = 2.9 Hz, 1H), 7.39 – 7.32 (m, 3H), 7.09 – 6.99 (m, 2H), 6.74 (dd, = 3.0, 8.8 Hz, 1H), 3.85 (s, 2H), 3.71 (s, 3H); 13C NMR (400 MHz, DMSO-d6): δ 170.4, 160.1, 141.1, 136.7, 130.0, 127.8, 124.4, 121.6, 119.2, 119.0, 111.9, 109.1, 105.4, 55.4, 34.4; MS: 315 (M+Na)+.

[051]Example 13:

N-(2-ethylphenyl)-2-(lH-indol-3-yl)acetamide (12):

Yield 78% ; 1H NMR (400 MHz, CDC13): δ 8.68 (brs, 1H), 7.95 (d, = 8.1 Hz, 1H), 7.67 (d, = 7.8 Hz, 1H), 7.48 – 7.44 (m, 2H), 7.29 – 7.23 (m, 1H), 7.22 – 7.20 (m, 3H), 7.05 (d, = 4.4 Hz, 2H), 2.00 (q, = 7.4 Hz, 2H), 0.67 (t, = 7.6 Hz, 3H); 13C NMR (100 MHz, CDC13): δ 169.9, 136.6, 135.0, 134.3, 128.7, 126.7, 125.1, 124.1, 123.0, 122.5, 120.4, 118.7, 111.6, 108.6, 34.4, 24.2, 13.6.

[052] Example 14:

N-(2-bromophenyl)-2-(lH-indol-3-yl)acetamide(13):

Yield 76%; 1H NMR (200 MHz, DMSO-d6): δ 11.00 (brs, 1H), 9.30 (s, 1H), 7.81 -7.77 (m, 1H), 7.63 – 7.56 (m, 2H), 7.41 – 7.35 (m, 3H), 7.11 – 7.05 (m, 3H), 3.85 (s, 2H);13C NMR (100 MHz, DMSO-d6): δ 169.9, 136.2, 132.5, 128.0, 127.2, 126.4, 125.5, 124.4, 121.2, 118.7, 118.5, 116.4, 111.4, 108.0, 33.2.

[053] Example 15:

N-benzyl-2-(lH-indol-3-yl)acetamide (14):

Yield 85%; 1H NMR (400 MHz, DMSO-d6): δ 10.89 (brs., 1H), 8.40 (t, = 5.7 Hz, 1H), 7.57 (d, = 7.8 Hz, 1H), 7.36 (d, = 8.1 Hz, 1H), 7.32 – 7.18 (m, 6H), 7.08 (t, = 7.5Hz, 1H), 7.03 – 6.90 (m, 1H), 4.28 (d, = 5.9Hz, 2H), 3.60 (s, 2H); 13C NMR (100 MHz, DMSO-de): δ 171.2, 140.1, 136.6, 128.7, 127.7, 127.2, 124.3, 121.4, 119.2, 118.7, 111.8, 109.3, 42.7, 33.2.

[054] Example 16:

2-(lH-indol-3-yl)-N-(4-methoxybenzyl)acetamide(15):

Yield 85% ; 1H NMR (400 MHz, DMSO-d6): δ 10.87 (brs, 1 H), 8.32 (t, = 5.6 Hz, 1 H), 7.55 (d, = 7.8 Hz, 1H), 7.35 (d, = 8.1 Hz, 1H), 7.22 – 7.13 (m, 3H), 7.11 – 7.05 (m, 1 H), 7.00 – 6.94 (m, 1H), 6.84 (d, = 8.6 Hz, 2H), 4.20 (d, = 6.1 Hz, 2H), 3.72 (s, 3H), 3.56 (s, 2H); 13C NMR (100 MHz, DMSO-d6): δ 171.1, 158.6, 136.6, 132.0, 129.0, 127.7, 124.2, 121.4, 119.2, 118.7, 114.1, 111.8, 109.4, 55.5, 42.1, 33.2.

[055] Example 17:

N,N-dibenzyl-2-(lH-indol-3-yl)acetamide (16):

Yield 70% ; 1H NMR (400 MHz, DMSO-d6): δ 10.91 (brs, 1H), 7.50 (d, = 7.8 Hz, 1H), 7.37 – 7.34 (m, 3H), 7.30 (d, = 6.6 Hz, 1H), 7.25 – 7.19 (m, 3H), 7.17 (t, = 6.6 Hz, 5H), 7.16 (d, = 7.8 Hz, 1H), 7.00 – 6.97 (m, 1H), 4.59 (s, 2H), 4.50 (s, 2H), 3.86 (s, 2H); 13C NMR (100 MHz, DMSO-d6): δ 171.7, 138.2, 136.6, 129.2, 128.8, 128.1, 127.8, 127.7, 127.5, 127.1, 124.2, 121.5, 119.2, 118.8, 111.8, 108.5, 50.7, 48.4, 31.2.

[056] Example 18:

2-(lH-indol-3-yl)-N-propylacetamide (17):

Yield 75% ; XH NMR (200 MHz, DMSO-d6): δ 10.86 (brs, 1H), 7.88 – 7.80 (m, 1H), 7.56 (d, = 7.6 Hz, 1H), 7.31 (d, = 7.8 Hz, 1H), 7.17 (d, = 2.3 Hz, 1H), 7.06 – 6.92 (m, 2H), 3.48 (s, 2H), 3.00 (q, J = 6.8 Hz, 2H), 1.39 (sxt, / = 7.2 Hz, 2H), 0.88 – 0.75 (t, = 7.2 Hz, 3H); 13C NMR (100 MHz, DMSO-d6): δ 171.0, 136.6, 127.8, 124.2,

121.4, 119.2, 118.7, 111.8, 109.6, 39.4, 33.3, 22.9, 11.9.

[057] Example 19:

N-hexyl-2-(lH-indol-3-yl)acetamide (18) :

Yield 87% ; 1H NMR (400 MHz, DMSO-d6): δ 10.84 (brs, 1H), 7.83 (brs, 1H), 7.54 (d, = 7.8 Hz, 1H), 7.33 (d, = 8.1 Hz, 1H), 7.21 – 7.13 (m, 1H), 7.06 (t, = 7.6 Hz, 1H), 6.96 (t, J = 7.5 Hz, 1H), 3.47 (s, 2H), 3.03 (q, / = 6.8 Hz, 2H), 1.37 (t, = 6.5 Hz, 2H), 1.30 – 1.15 (m, 6H), 0.84 (t, = 6.7 Hz, 3H); 13C NMR (100 MHz, DMSO-d6): δ 170.9, 136.6, 127.7, 124.2, 121.3, 119.1, 118.7, 111.7, 109.5, 39.06, 33.2, 31.5, 29.6, 26.5, 22.5, 14.4.

[058] Example 20:

Methyl (2-(lH-indol-3-yl)acetyl)-L-alaninate (19):

Yield 79% ; 1H NMR (400 MHz, CDC13): δ 8.53 (brs, 1H), 7.60 (d, = 7.8 Hz, 1H), 7.41 (d, = 8.1 Hz, 1H), 7.25 – 7.23 (m, 1H), 7.19 – 7.14 (m, 2H), 6.27 (d, = 7.3 Hz, 1H), 4.63 (t, = 7.3 Hz, 1H), 3.78 (s, 2H), 3.68 (s, 3H), 1.31 (d, = 7.3 Hz, 3H); 13C NMR (100 MHz, CDC13): δ 173.4, 171.2, 136.4, 127.0, 123.8, 122.5, 119.9, 118.7,

111.5, 108.5, 52.4, 48.0, 33.3, 18.2.

[059] Example 21:

-(6-chloro-lH-indol-3-yl)-N-phenylacetamide(20):

To a solution of 6-Chloro indole 20a (300 mg, 1.98 mmol )in anhydrous THF, Oxalyl chloride (186 μΤ, 276 mg, 2.18 mmol) was added and the mixture stirred at room temperature. After 2 h, N,N-Diisopropylethylamine (758 μΤ, 562 mg, 4.35 mmol) was

introduced to the mixture, followed by the aniline (221.0 mg, 2.37 mmol). The temperature was raised to 45 °C, and heating continued for 18 h. The solvent was evaporated, and then mixture was diluted with EtOAC (15 mL), washed with brine and dried over anhydrous Na2S04. The crude material obtained after removal of solvent was purified by column chromatography (10 – 20% EtOAc : Petroleum ether) to afford 20b (295 mg, 51% yield) as a yellow coloured solid. IR Omax(film): 3346, 3307,2853, 1724, 1678 cm“1; 1H NMR (400 MHz, DMSO-d6): δ 12.40 (br. s., 1H), 10.68 (s, 1H), 8.79 (d, = 3.2 Hz, 1H), 8.25 (d, = 8.6 Hz, 1H), 7.85 (d, = 7.8 Hz, 2H), 7.62 (d, = 1.7 Hz, 1H), 7.41 – 7.30 (m, 3H), 7.19 – 7.13 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 182.5, 162.5, 140.0, 138.4, 137.4, 129.2, 128.5, 125.4, 124.8, 123.4, 122.9, 120.8, 113.0, 112.3; HRMS (ESI) Calculated for Ci6HnN2OCl[M+H]+: 299.0582, found 299.0580;

A solution of 20b (300 mg, 0.99 mmol) dissolved in MeOH (40 mL) was added to NaBH4 (45 mg, 1.23 mmol). The reaction was stirred for 4h and then added to saturated solution of Na2S04. The reaction mixture was further stirred for lh and then filtered through Celite.The filtrate obtained was concentrated in vacuo, and then mixture was diluted with EtOAc (15 mL), washed with brine and dried over anhydrous Na2S04. The crude material obtained after removal of solvent was forwarded for next step without further purification.In an N2 atmosphere, TMSC1 (1.272 mL, 9.9 mmol) in CH3CN (40 mL) was added to sodium iodide (1.488 mg, 9.9 mmol) and stirred for 2h. The reaction mixture was cooled to 0 °C and a solution of above crude alcohol (0.99 mmol) in CH3CN (10 mL) was then added drop wise over 30 min, followed by stirring for 3h. The reaction mixture was poured into NaOH (7g in 40 mL of water) and then extracted with ethyl acetate (15×2). The organic layer was washed with aq.Na2S203, dried over Na2S04 and concentrated in vacuo. The residue was chromatographed on silica gel (EtOAc:Pet ether) to afford 20 as a off white solid (two steps 38 % ); IR Umax(film): 3273, 3084,2953, 2857, 1629, 1562 cm“1; 1H NMR (400 MHz, DMSO-d6): δ 11.06 (br. s., 1H), 10.13 (br. s., 1H), 7.62 – 7.57 (m, 3H), 7.40 (s, 1H), 7.30 – 7.25 (m, 3H), 7.04 – 6.99 (m, 2H), 3.71 (s, 2H); 13C NMR (100 MHz, DMSO-d6): δ 170.1,

139.7, 136.9, 129.2, 126.5, 126.3, 125.5, 123.7, 120.6, 119.6, 119.3, 111.5, 109.4, 34.0; HRMS (ESI):Calculated for Ci6Hi4N2OCl[M+H]+: 285.0789, found 285.0786.

[060] Example 22:

2-(5-chloro-lH-indol-3-yl)-N-phenylacetamide(21):

21a 21b 21

To a solution of 5-Chloro indole 21a (300 mg, 1.98 mmol )in anhydrous THF(20 mL), Oxalyl chloride (186 ^L, 276 mg, 2.18 mmol) was added and the mixture stirred at room temperature. After 2 h, N,N-diisopropylethylamine (758 μΕ, 562 mg, 4.35 mmol) was introduced to the mixture, followed by the aniline (221.0 mg, 2.37 mmol). The tempera ture was raised to 45 °C, and heating continued for 18 h. The solvent was evaporated, and then mixture was diluted with EtOAC (15 mL), washed with brine and dried over anhydrous Na2S04. The crude material obtained after removal of solvent was purified by column chromatography (10 – 20% EtOAc : Petroleum ether) to afford (21b) (305 mg, 53% yield) as a yellow coloured solid. IR rjmax(film): 3346, 3307,2853, 1724, 1678 cm“1; 1H NMR (400 MHz, DMSO-d6): δ 12.40 (br. s., 1H), 10.68 (s, 1H), 8.79 (d, = 3.2 Hz, 1H), 8.25 (d, = 8.6 Hz, 1H), 7.85 (d, = 7.8 Hz, 2H), 7.62 (d, = 1.7 Hz, 1H), 7.42 – 7.30 (m, 3H), 7.20 – 7.14 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 182.4, 162.4, 140.3, 138.4, 135.4, 129.2, 127.9, 124.8, 124.1, 120.8, 114.8, 112.0; HRMS (ESI) Calculated for Ci6HnN2OCl[M+H]+: 299.0582, found 299.0580; A solution of 21b (200 mg, 0.66 mmol) dissolved in MeOH (30 mL) was added to NaBH4 (30 mg, 0.82 mmol). The reaction was stirred for 4h and then added to saturated solution of Na2S04. The reaction mixture was further stirred for lh and then filtered through Celite. The filtrate obtained was concentrated in vacuo, and then mixture was diluted with EtOAc (15 mL), washed with brine and dried over anhydrous Na2S04. The crude material obtained after removal of solvent was forwarded for next step without further purification. In an N2 atmosphere, TMSC1 (848 mL, 6.6 mmol) in CH3CN (25 mL) was added to sodium iodide (992 mg, 6.6 mmol) and stirred for 2h. The reaction mixture was cooled to 0 °C and a solution of above crude alcohol(0.66 mmol) in CH3CN (5 mL) was then added dropwise over 30 min, followed by stirring for 3h. The reaction mixture was poured into NaOH (5g in 30 mL of water) and then extracted with ethyl acetate(15×2). The organic layer was washed with aq.Na2S203, dried over Na2S04 and concentrated in vacuo. The residue was chromatographed on silica gel (EtOAc:Pet ether) to afford 22 as a off white solid (two steps 42 % ); IR Umax(film): 3273, 3084,2955, 2857, 1629, 1562 cm“1; 1H NMR (400 MHz, DMSO-d6): δ 11.13 (br. s., 1H), 10.11 (s, 1H), 7.67 (s, 1H), 7.60 (d, = 7.8 Hz, 2H), 7.39 – 7.27 (m, 4H), 7.13 – 7.02 (m, 2H), 3.16 (s, 2H); 13C NMR (100 MHz, DMSO-d6): δ 169.9, 139.8, 135.0, 129.2, 128.9, 126.2, 123.6, 121.4, 119.6, 118.6, 113.4, 109.0, 34.0; HRMS (ESI) Calculated for Ci6H14N2OCl[M+H]+: 285.0789, found 285.0786.

[061] Example 23:

2-(l-benzyl-lH-indol-3-yl)-N-phenylacetamide (22):

Yield 79% ; 1H NMR (400 MHz, DMSO-d6): δ 7.67 (d, = 7.8 Hz, 1H), 7.54 (brs, 1H), 7.43 – 7.31 (m, 6H), 7.31 – 7.25 (m, 3H), 7.23 – 7.15 (m, 4H), 7.12 – 7.06 (m, 1H), 5.36 (s, 2H), 3.91 (s, 2H); 13C NMR (100 MHz, DMSO-d6): δ 169.7, 137.7, 137.2, 137.0, 128.9, 128.9, 127.9, 127.6, 126.9, 124.3, 122.7, 120.2, 119.9, 119.0, 110.2, 107.9, 77.4, 77.1, 76.8, 50.1, 34.5.

[062] Example 24:

Procedure B:

2-(lH-indol-3-yl)-N-phenylacetamidel(100 mg; 0.4 mmol) was dissolved in DCM:MeOH(50 mL; 5: 1), then a stream of 03 was passed through the solution until a blue color developed (10 min). The 03 stream was continued for 4 min. Then surplus O3 was removed by passing a stream of 02 through the solution for 10 min or until the blue colorcompletely vanished. Afterwards pyridine (0.1 mL;1.2mmol) was added to the cold (- 78 °C) mixture. The mixture was allowed to warm to room temperature (1 h) and then Et3N (0.35 mL; 2.4 mmol) were added. After stirring at room temperature overnight the reaction mass was concentrated under reduced pressure to dryness, diluted with EtOAc (30 mL), washed with H20 (5 mL), brine (5 mL), and dried over Na2S04. The crude material obtained after removal of solvent was purified by column chromatography (silica gel 230-400 mesh, MeOH – DCM) to give desired quinolone carboxamide as colorless solid.

[063] Example 25:

4-oxo-N-phenyl-l,4-dihydroquinoline-3-carboxamide (23):

Yield: 65 mg; 62%; XH NMR (200MHz ,DMSO-d6) δ = 12.97 (brs, 1 H), 12.49 (s, 1 H), 8.89 (s, 1 H), 8.33 (d, J = 8.2 Hz, 1 H), 7.91 – 7.69 (m, 4 H), 7.62 – 7.50 (m, 1 H), 7.37 (t, J = 7.8 Hz, 2 H), 7.18 – 7.01 (m, 1 H); MS: 287 (M+Na)+.

[064] Example 26:

2,4-di-tert-butyl-5-(4-oxo-l,4-dihydroquinoline-3-carboxamido)phenyl methyl carbonate (24):

Yield: 35 mg; 34%; 1H NMR (400MHz ,DMSO-d6) δ = 12.96 (brs, 1 H), 12.08 (s, 1 H), 8.94 – 8.82 (m, 1 H), 8.44 – 8.28 (m, 1 H), 7.86 – 7.79 (m, 1 H), 7.78 – 7.73 (m, 1 H), 7.59 (s, 1 H), 7.53 (t, J = 7.5 Hz, 1 H), 7.39 (s, 1 H), 3.86 (s, 3 H), 1.46 (s, 9 H), 1.32 (s, 9 H).

[065] Example 27:

(S)-4-oxo-N-(l-phenylethyl)-l,4-dihydroquinoline-3-carboxamide (25):

Yield: 56 mg; 53%; 1H NMR (500MHz ,DMSO-d6) δ = 12.75 (brs, 1H), 10.54 (d, J = 7.6 Hz, 1H), 8.73 (brs, 1H), 8.28 (d, J = 7.9 Hz, 1H), 7.78 (d, J = 7.9 Hz, 1H), 7.73 -7.68 (m, 1 H), 7.50 (t, J = 7.5 Hz, 1 H), 7.42 – 7.34 (m, 4 H), 7.29 – 7.23 (m, 1 H), 5.18 (t, J = 7.2 Hz, 1 H), 1.50 (d, J = 6.7 Hz, 3 H).

[066] Example 28:

Synthesis of ivacaftor (26):

To a solution of 2,4-di-tert-butyl-5-(4-oxo-l,4-dihydroquinoline-3-carboxamido)phenyl methyl carbonate 5 (30 mg, 0.06mmol) in MeOH (2 mL) was added NaOH (5.3 mg, 0.13mmol) dissolved in H20 (2 mL), and the reaction mixture was stirred at room temperature for 5h. Reaction mass was evaporated to one third of its volume (temperature not exceeding 40°C) and acidified with aq.2N HC1 to pH 2-3. The resulting precipitate was collected by suction filtration give desired compound 7 (19 mg, 76%) as off white solid H NMR (400MHz ,DMSO-d6) δ = 12.88 (d, J = 6.6 Hz, 1 H), 11.81 (s, 1 H), 9.20 (s, 1 H), 8.86 (d, J = 6.6 Hz, 1 H), 8.32 (d, J = 7.8 Hz, 1 H), 7.88 – 7.65 (m, 2 H), 7.51 (t, J = 7.5 Hz, 1 H), 7.16 (s, 1 H), 7.10 (s, 1 H), 1.38 (s,9H), 1.36 (s, 9H).

[067] Example 29:

N-(4-fluorophenyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide (27):

Yield 56% ; 1H NMR (400 MHz, DMSO-d6): δ 12.96 (br. s., 1H), 12.50 (s, 1H), 8.88 (s, 1H), 8.33 (d, = 7.3 Hz, 1H), 7.86 – 7.72 (m, 4H), 7.54 (t, = 7.3 Hz, 1H), 7.20 (t, = 8.8 Hz, 2H); 13C NMR (400 MHz, DMSO-d6): δ 176.8, 163.2, 159.7, 157.3, 144.6, 139.6, 135.7, 133.5, 126.4, 125.9, 125.8, 121.8, 119.7, 116.1, 115.9, 110.9.

[068] Example 30:

N-(4-chlorophenyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide (28):

Yield 51% ; 1H NMR (400 MHz, DMSO-d6): δ 13.00 (brs., 1H), 12.59 (br. s., 1H), 8.89 (s, 1H), 8.34 (d, = 7.6 Hz, 1H), 7.83 – 7.76 (m, 4H), 7.56 (s, 1H), 7.42 (d, = 7.9 Hz, 2H); 13C NMR (400 MHz, DMSO-d6): δ 176.8, 163.4, 144.7, 139.6, 138.2, 133.5, 129.4, 127.4, 126.4, 125.9, 125.8, 121.6, 119.7, 110.8.

[069] Example 31:

4-oxo-N-(p-tolyl)-l,4-dihydroquinoline-3-carboxamide (29):

Yield 57% ; 1H NMR (400 MHz, DMSO-d6): δ 12.94 (brs., 1H), 12.40 (s, 1H), 8.88 (s, 1H), 8.33 (d, = 7.8Hz, 1H), 7.82 – 7.80 (m, 1H), 7.76 – 7.7 (m, 1H), 7.63 (d, = 8.3 Hz, 2H), 7.53 (t, = 7.3 Hz, 1H), 7.17 (d, = 8.1 Hz, 2H), 2.29 (s, 3H); 13C NMR (100 MHz, DMSO-de): δ 176.8, 163.1, 144.5, 139.6, 136.8, 133.4, 132.8, 129.9, 126.4, 125.9, 125.7, 120.0, 119.6, 111.1, 20.9; HRMS (ESI):Calculated for Ci7H1502N2[M+H]+: 279.1128, found 279.1127.

[070] Example 32:

N-(4-ethylphenyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide (30):

Yield 51% ; 1H NMR (400 MHz, DMSO-d6): δ 12.95 (br. s., 1H), 12.40 (d, = 7.8 Hz, 1H), 8.87 (d, = 6.1 Hz, 1H), 8.33 (d, = 8.1 Hz, 1H), 7.81 – 7.76 (m, 2H), 7.66 – 7.62 (m, = 8.3 Hz, 2H), 7.53 (t, 7 = 7.5 Hz, 1H), 7.22 – 7.17 (m, = 8.3 Hz, 2H), 2.58 (q, = 7.6 Hz, 2H), 1.18 (t, = 7.6 Hz, 3H); 13C NMR (400 MHz, DMSO-d6): δ 181.5, 167.8, 149.3, 144.3, 144.0, 141.7, 138.2, 133.4, 131.1, 130.7, 130.5, 124.8, 124.4, 115.9, 32.8, 20.9.

[071] Example 33:

4-Oxo-N-(4-propylphenyl)-l,4-dihydroquinoline-3-carboxamide (31):

Yield 51%; 1H NMR (500 MHz, DMSO-d6): δ12.93 (brs, 1H), 12.40 (s, 1H), 8.87 (s, 1H), 8.36 – 8.29 (m, 1H), 7.86 – 7.78 (m, 1H), 7.75 (d, J= 7.9 Hz, 1H), 7.68 – 7.61 (m, J= 8.2 Hz, 2H), 7.54 (t, J= 7.6 Hz, 1H), 7.22 – 7.14 (m, J= 8.2 Hz, 2H), 2.55 – 2.51 (m, 2H), 1.64 – 1.53 (m, 2H), 0.90 (t, J= 7.3 Hz, 3H); 13C NMR (500 MHz, DMSO-d6): 176.8, 163.1, 144.5, 139.6, 137.6, 137.0, 133.5, 129.3, 126.4, 125.9, 125.7, 120.0, 119.7, 111.1, 37.2, 24.6, 14.1.

[072] Example 34:

N-(4-isopropylphenyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide (32):

Yield 46% ; 1H NMR (500 MHz, DMSO-d6): δ 12.93 (br. s., 1H), 12.40 (br. s., 1H), 8.89 – 8.86 (m, 1H), 8.33(d, = 7.6 Hz, 1H), 7.81 – 7.50 (m, 5H), 7.25 – 7.21 (m, 2H), 2.90-2.83 (m, 1H), 1.22-1. l l(m, 6H); 13C NMR (100 MHz, DMSO-d6): δ 176.8, 163.1, 144.5, 143.9, 139.6, 137.1, 133.4, 127.2, 126.4, 125.9, 125.7, 120.1, 119.6, 111.1, 33.4, 24.4.

[073] Example 35:

4-oxo-N-(4-(trifluoromethoxy)phenyl)-l,4-dihydroquinoline-3-carboxamide(33):

Yield 57% ; 1H NMR (400 MHz, DMSO-d6): δ 12.98 (br. s., 1H), 12.63 (s, 1H), 8.88 (d, = 4.9 Hz, 1H), 8.32 (d, = 7.8 Hz, 1H), 7.89 – 7.83 (m, = 8.8 Hz, 2H), 7.79 (d, = 7.6 Hz, 1H), 7.77 – 7.73 (m, 1H), 7.53 (t, J = 7.5 Hz, 1H), 7.40 – 7.34 (m, = 8.6 Hz, 2H); 13C NMR (100 MHz, DMSO-d6): δ 176.8, 163.5, 144.7, 144.0, 139.5, 138.5, 133.5, 126.3, 125.9, 125.8, 122.3, 121.4, 119.7, 110.7.

[074] Example 36:

N-(2-chloro-5-methoxyphenyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide(34):

Yield 54% ; XH NMR (400 MHz, DMSO-d6): δ 12.98 (br. s., 1H), 12.49 (s, 1H), 8.88 (s, 1H), 8.33 (d, = 7.8 Hz, 1H), 7.83 – 7.75 (m, 1H), 7.56-7.48 (m, 3H), 7.27 – 7.21 (m, 1H), 6.67 (d, = 7.8 Hz, 1H), 3.77 (s, 3H); 13C NMR (400 MHz, DMSO-d6): δ 176.8, 163.4, 160.2, 144.7, 140.4, 139.6, 133.5, 130.3, 126.4, 125.9, 125.8, 119.7, 112.3, 111.0, 109.5, 105.7, 55.5.

[075] Example 37:

N-(2-ethylphenyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide(35):

Yield 58% ; 1H NMR (400 MHz, DMSO-d6): δ 12.94 (br. s., 1H), 12.37 (s, 1H), 8.90 (s, 1H), 8.36 (dd, = 8.1, 1.4 Hz, 2H), 8.32 (dd, = 8.1, 1.4 Hz, 2H), 7.82 – 7.74 (m, 1H), 7.53- 7.19 (m, 3H), 7.15 – 7.06(m, 1H), 2.79 (q, = 7.3 Hz, 2H), 1.26 (t, = 7.5 Hz, 3H); 293 (M+H)+.

[076] Example 38:

N-(2-bromophenyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide(36):

Yield 47% ; 1H NMR (200 MHz, DMSO-d6): δ 12.98 (br. s., 1H), 12.69 (s, 1H), 8.90 (d, = 5.9 Hz, 1H), 8.54 (dd, 7 = 1.4, 8.3 Hz, 1H), 8.34 (d, = 7.6 Hz, 1H), 7.86 – 7.67 (m, 3H), 7.57 – 7.49 (m, 1H), 7.40 (t, = 7.2 Hz, 1H), 7.10 – 7.05 (m, 1H); 13C NMR (100 MHz, DMSO-de): δ 176.7, 163.7, 145.0, 139.5, 137.7, 133.5, 133.1, 128.6, 126.4, 126.0, 125.8, 125.3, 122.9, 119.7, 113.4, 110.8.

[077] Example 39:

N-benzyl-4-oxo-l,4-dihydroquinoline-3-carboxamide(37):

Yield 58% ; 1H NMR (400 MHz, CD3OD-d6): δ 8.82 (s, 1 H), 8.35 (d, = 8.1 Hz, 1 H), 7.79 – 7.77 (m, 1 H), 7.65 (d, = 8.3 Hz, 1 H), 7.52 (t, = 7.6 Hz, 1 H), 7.42 – 7.34 (m, 4 H), 7.31 – 7.26 (m, 1 H), 4.67 (s, 2 H); 13C NMR (400 MHz, DMSO-d6): δ 176.6, 165.0, 144.2, 140.0, 139.5, 133.2, 128.9, 128.7, 127.8, 127.3, 126.6, 125.9, 125.4, 119.5, 111.2, 42.6.

[078] ] Example 40:

N-(4-methoxybenzyl)-4-oxo-l,4-dihydroquinoline-3-carboxamide(38):

Yield 56% ; 1H NMR (400 MHz, DMSO-d6): δ 12.73 (br. s., 1H), 10.35 (t, = 5.3 Hz, 1H), 8.78 (d, = 6.1 Hz, 1H), 8.24 (d, = 8.1 Hz, 1H), 7.76 (d, = 7.1 Hz, 1H), 7.73 -7.68 (m, 1H), 7.48 (t, = 7.5 Hz, 1H), 7.28 (d, = 8.3 Hz, 2H), 6.91 (d, = 8.1 Hz, 2H), 4.49 (d, = 5.6 Hz, 2H), 3.74 (s, 3H); 13C NMR (100 MHz, DMSO-d6): δ 176.6, 164.8, 158.8, 144.1, 139.5, 133.1, 131.9, 129.2, 126.6, 125.8, 125.4, 119.5, 114.3, 111.3, 55.5, 42.0.

[079] Example 41:

N,N-dibenzyl-4-oxo-l,4-dihydroquinoline-3-carboxamide(39):

Yield 43% ; 1H NMR (400 MHz, DMSO-d6): δ 12.21 (br. s., 1H), 8.27 (d, = 4.9 Hz, 1H), 8.21 (d, = 7.6 Hz, 1H), 7.49 – 7.41 (m, 2H), 7.41 – 7.35 (m, 3H), 7.33 – 7.20 (m, 5H), 7.20 – 7.11 (m, 7 = 7.1 Hz, 2H), 4.59 (br. s., 2H), 4.42 (s, 2H).

[080] Example 42:

4-oxo-N-propyl-l,4-dihydroquinoline-3-carboxamide(40):

Yield 47% ;1H NMR (400 MHz, DMSO-d6): δ 12.7 (br.s., 1H)10.05 (t, = 5.5 Hz, 1H), 8.74 (s, 1H), 8.26 (d, = 8.1 Hz, 1H), 7.83 – 7.66 (m, 2H), 7.52 – 7.44 (m, 1H), 3.33 – 3.22 (m, 2H), 1.61 – 1.49 (m, 2H), 0.93 (t, = 7.5 Hz, 3H); 13C NMR (100 MHz, DMSO-de): δ 176.6, 164.8, 143.9, 139.5, 133.1, 126.6, 125.9, 125.3, 119.4, 111.4, 39.3, 23.1, 12.0

[081] Example 43:

N-hexyl-4-oxo-l,4-dihydroquinoline-3-carboxamide(41):

Yield 51% ;1H NMR (400 MHz, DMSO-d6): δ 12.68 (m, 1H), 10.02 (t, = 5.5 Hz, 1H), 8.73 (d, = 6.1 Hz, 1H), 8.27 – 8.25 (m, 1H), 7.77 – 7.67 (m, 2H), 7.47 (t, = 7.5 Hz, 1H), 3.33 – 3.29 (m, 2H), 1.56 – 1.45 (m, 2H), 1.34 – 1.25 (m, 6H), 0.88 – 0.82 (m, 3H); 13C NMR (100 MHz, DMSO-d6): δ 176.6, 164.8, 143.9, 139.5, 133.1, 126.6, 125.9, 125.3, 119.4, 111.4, 38.7, 31.5, 29.8, 26.7, 22.5, 14.4.

[082] Example 44:

Methyl (4-oxo-l,4-dihydroquinoline-3-carbonyl)-L-alaninate(42):

Yield 38% ; 1H NMR (400 MHz, CD3OD): δ 8.74 (s, 1H), 8.47 – 8.29 (m, 1H), 7.86 -7.76 (m, 1H), 7.64 (d, = 8.3 Hz, 1H), 7.58 – 7.44 (m, 1H), 4.69 (d, = 7.3 Hz, 1H), 3.79 (s, 3H), 1.55 (d, = 7.3 Hz, 3H); 13C NMR (100 MHz, CD3OD): δ 177.3, 173.3, 165.5, 143.6, 139.2, 132.9, 126.3, 125.4, 125.2, 118.5, 110.3, 51.5, 47.0, 17.0.

[083] Example 45:

7-chloro-4-oxo-N-phenyl-l,4-dihydroquinoline-3-carboxamide(43):

Yield 48% ; IR Omax(film): 2920, 2868, 1661, 1601 cm” 1; 1H NMR (400 MHz, DMSO-de): δ 12.91 (br. s., 1H), 12.30 (s, 1H), 8.90 (s, 1H), 8.29 (d, = 8.8 Hz, 1H), 7.80 -7.67 (m, 3H), 7.58 – 7.51 (m, 1H), 7.36 (t, = 7.7 Hz, 2H), 7.09 (t, = 7.3 Hz, 1H); 13C NMR (100 MHz, DMSO-d6): δ 176.3, 162.9, 145.4, 140.3, 139.2, 138.0, 129.5, 128.2, 126.1, 125.1, 123.9, 120.1, 118.8, 111.6.

[084] Example 46:

6-chloro-4-oxo-N-phenyl-l,4-dihydroquinoline-3-carboxamide(44):

Yield 52% ; 1H NMR (400 MHz, DMSO-d6): δ 13.05 (brs, 1H), 12.27 (s, 1H), 8.88 (s, 1H), 8.21 (d, = 2.2 Hz, 1H), 7.86 – 7.67 (m, 4H), 7.36 (t, = 7.8 Hz, 2H), 7.16 – 7.04 (m, 1H); 13C NMR (100 MHz, DMSO-d6): δ 175.6, 162.9, 144.9, 139.1, 138.2, 133.5, 130.4, 129.5, 127.5, 124.9, 123.9, 122.0, 120.1, 111.4.

[085] Example 47:

l-benzyl-4-oxo-N-phenyl-l,4-dihydroquinoline-3-carboxamide(45)

Yield 55% ; 1H NMR (400 MHz, DMSO-d6): δ 12.30 (s, 1H), 9.05 (s, 1H), 8.60 (dd, = 1.7, 8.1 Hz, 1H), 7.82 (d, = 7.8 Hz, 2H), 7.69 – 7.62 (m, 1H), 7.55 – 7.45 (m, 2H), 7.43 – 7.34 (m, 5H), 7.24 – 7.18 (m, 2H), 7.17 – 7.10 (m, 1H), 5.53 (s, 2H); 13C NMR (100 MHz, DMSO-d6): δ 176.9, 162.9, 148.7, 139.3, 138.7, 134.1, 133.1, 129.4, 128.9, 128.7, 128.0, 127.4, 126.2, 125.5, 123.9, 120.5, 116.9, 112.3, 57.9; HRMS (ESI): Calculated for C23H1802N2Na [M+Na]+: 377.1260, found 377.1259; MS: 355 (M+H)+.

[086] Advantages of invention:

1. Cost-effective process for synthesis.

2. Carried out at environmentally benign conditions.

3. Short synthetic route.

4. Useful for making several related compounds of medicinal

 

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DR SRINIVASA REDDY recieving NASI – Reliance Industries Platinum Jubilee Award (2015) for Application Oriented Innovations in Physical Sciences.

 

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MYSELF WITH HIM

 

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From left to right: Dr. D. Srinivasa Reddy, Shri Y. S. Chowdary, Dr. Harsh Vardhan, Dr. Girish Sahni

  • Dr D. Srinivasa Reddy receiving the prestigious “SHANTI SWARUP BHATNAGAR” award at the occasion of the 75th Foundation day of CSIR.

Shanti Swarup Bhatnagar awardees with the honorable Prime Minister of India

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NCL PUNE

DSR Group

//////////WO-2016181414, WO 2016181414,  IVACAFTOR, new patent, COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH,  Anusandhan Bhawan, Rafi Marg New Delhi, INDIA, CSIR, Dr. D. Srinivasa Reddy

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Oct 312013
 

IUPAC Name: [(2S,4R,5R,5aS,6S,8S,9aR,10aS)-5,6-diacetyloxy-2,8-dihydroxy-10a-(2-hydroxypropan-2-yl)-3,5a-dimethyl-9-methylidene-2,4,5,6,7,8,9a,10-octahydro-1H-benzo[g]azulen-4-yl] benzoate | CAS Registry Number: 134955-83-2

Synonyms: Brevifoliol, CHEBI:555808, CID178222, 134955-83-2

Brevifoliol was first isolated from the leaves of the plant Taxus brevifolia (F. Balza et al Phytochemistry 30, p. 1613-1614 (1991)). The process of its isolation involved extracting the fresh leaves of Taxus wallichiana with ethyl alcohol to get an extract. The crude extract after concentration was diluted with water and partitioned between hexane, chloroform and ethyl acetate sequentially. The chloroform extract upon concentration yielded a dark brown residue. The resultant residue was subjected to column chromatography over silica gel and eluted with chloroform and chloroform-methanol gradient. Six fractions were collected and brevifoliol was isolated from fraction five by rechromatography over silica gel and eluting with hexane-ethyl acetate gradient.

 

Brevifoliol has been isolated from other species of Taxus including the Himalayan yew Taxus wallichiana which is available in India., Recently, the structure of brevifoliol has been revised and it was shown to belong to 11 (15→1) abeo taxoid bicyclic skeleton of formula (1). The isolation of brevifoliol from leaves of the plantTaxus wallichiana is also reported in S. K. Chattopadhyay et al Indian J. Chemistry 35B, 175-177(1996) as part of studies on the isolation of anticancer compounds. The process of this disclosure involved extracting the dried and crushed needles of Taxus wallichiana with methanol for 72 hours and the extract was concentrated in vacuo. The concentrate was diluted with water and extracted with hexane and chloroform respectively. Concentration of the chloroform phase under vacuum left a residue which was separated by column chromatography over silica gel. Fraction eluted with chloroform-methanol (98:5) contained brevifoliol which was further purified by re-chromatography over silica gel and eluted with chloroform-methanol (99:2). Fractions containing brevifoliol were combined and concentrated and recrystallized from pet-ether and ethyl acetate mixture to get brevifoliol as needles. In in vitro testing of brevifoliol, it was found to have significant anticancer activity against different cancer cell lines. The detection of anticancer activity in brevifoliol prompted the present investigators to develop an efficient processing technology for isolation of the compound in large quantities from the needles of the plant for further biological testing.

The prior art process of isolation of brevifoliol suffers from a number of disadvantages including partitioning of the aqueous extract with hexane and chloroform and repeated column chromatography to get the compound. Although the partitioning of the aqueous phase with organic solvents works on small scale, it forms thick emulsions on large scale partitioning process and creates hindrance in getting the fractions separated. Also, the use of repeated chromatography might be useful on small-scale isolation of brevifoliol, it is only cumbersome, tedious and not economical on large-scale process.

Felipe Balza, et al., “Brevifoliol, A Taxane From Taxus Brevifolla“, Phytochemistry, Pergamon Press, GB, vol. 30, No. 5, 1991, pp. 1613-1614

Patent No. U.S. 7,579,491

https://www.google.co.in/patents/US7579491?dq=US+7579491&hl=en&sa=X&ei=eRVyUp2SIcLOrQeMiIDQBw&ved=0CDcQ6AEwAA

Figure US07579491-20090825-C00002


Assignee: Council of Scientific and Industrial Research, New Delhi, India

Title or Subject: Process for Preparing Brevifoliol
Brevifoliol  is found in the leaves of the plants of the genus Taxus and is useful as an anticancer agent. This patent describes a method of extracting from the leaves of the plantTaxus wallichiana (Tw) Alternative methods are known for extracting from Tw but they are said to suffer from several disadvantages. These include partitioning of an aqueous extract with hexane and CHCl3 and the repeated use of chromatography to obtain the purified compound. The partitioning is said to work well on a small scale, but on a large scale thick emulsions are formed. Hence, the objective of the work in this patent is to provide a process that can be operated on a large scale. The process developed comprises the following steps:
  • (i) Dry and pulverize the leaves of the plant.
  • (ii) Extract the dried leaves with an alcohol such as MeOH or EtOH at 20−40 °C over 3 days.
  • (iii) Concentrate the alcoholic solution and adsorb the extract onto Celite.
  • (iv) Dry the Celite adsorbate at 20−50 °C for up to 48 h.
  • (v) Extract the dried adsorbate with 60−80 petroleum ether then CHCl3 and concentrate the CHCl3 extract.
  • (vi) Subject the concentrated mixture to gross fractionation over a column of silica gel using CHCl3 add 2% MeOH in CHCl3.
  • (vii) Subject the later eluate to further chromatography over alumina in petroleum ether using 10% EtOAc in petroleum ether.
  • (viii) Recrystallise  from EtOAc/petroleum ether as needles.
Brevifoliol

Advantages


The patent claims that the solvents can be recycled so that the process is cost-effective. Certainly it is true that avoiding water removes the emulsification problem, but two chromatographic steps are involved, and the use of so many solvents would seem to create handling problems on a commercial plant.
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Process for synthesis of chiral 3-substituted tetrahydroquinoline derivatives……..WO 2013140419…CSIR INDIA PATENT

 drugs, Uncategorized  Comments Off on Process for synthesis of chiral 3-substituted tetrahydroquinoline derivatives……..WO 2013140419…CSIR INDIA PATENT
Oct 012013
 

sumanirole

179386-43-7
179386-44-8 (maleate)

 

Sumanirole maleate, U-95666 (free base), U-95666E, PNU-95666E

Process for synthesis of chiral 3-substituted tetrahydroquinoline derivatives
Council Of Scientific & Industrial Research
The present invention relates to novel and concise process for the construction of chiral 3-substituted tetrahydroquinoline derivatives based on proline catalyzed asymmetric α-functionalization of aldehyde, followed by in situ reductive cyclization of nitro group under catalytic hydrogenation condition with high optical purities. Further the invention relates to conversion of derived chiral 3-substituted tetrahydroquinoline derivatives into therapeutic agents namely (-)-sumanirole (96% ee) and 1-[(S)-3-(dimethylamino)-3,4-dihydro-6,7-dimethoxy-quinolin-1(2H)-yl]propanone[(S)-903] (92% ee).
Process,sumanirole
Indications Restless legs syndrome; Parkinsons disease
Target-based Actions Dopamine D2 receptor agonist
Other Actions Anxiolytic; Antiparkinsonian
Inventors Boopathi, Senthil, Kumar; Arumugam, Sudalai; Rawat, Varun
IPC Codes C07D 215/20; C07D 471/06; C07D 215/38
DRUG      sumanirole
Publication Date 26-Sep-2013         WO-2013140419-A1

Sumanirole (PNU-95,666) is a highly selective D2 receptor full agonist, the first of its kind to be discovered. It was developed for the treatment of Parkinson’s disease andrestless leg syndrome. While it has never been approved for medical use  it is a highly valuable tool compound for basic research to identify neurobiological mechanisms that are based on a dopamine D2-linked (vs. D1, D3, D4, and D5-linked) mechanism of action

sumanirole

 

OTHER INFO

D-Phenylalanine (I) was protected as the methyl carbamate (II) by acylation with methyl chloroformate under Schotten-Baumann conditions. The N-methoxy amide (III) was then prepared by coupling of (II) with O-methyl hydroxylamine in the presence of EDC. Cyclization of (III) to the N-methoxy quinolinone (IV) was accomplished by treatment with bis(trifluoroacetoxy)iodobenzene in the presence of trifluoroacetic acid. Simultaneous reduction of the N-methoxy lactam and carbamate functions of (IV) by means of borane-methyl sulfide complex provided diamine (V). The aliphatic amino group of (V) was then selectively protected as the benzyl carbamate (VI) by using N-(benzyloxycarbonyloxy)succinimide at -40 C. Reaction of (VI) with phosgene, followed by treatment of the intermediate carbamoyl chloride with O-methyl hydroxylamine gave rise to the N-methoxy urea derivative (VII). This was cyclized with bis(trifluoroacetoxy)iodobenzene to the imidazoquinolinone (VIII). The N-methoxy and N-benzyloxycarbonyl groups of (VIII) were then removed by hydrogenolysis in the presence of Pearlman’s catalyst, and the title compound was finally converted to the corresponding maleate salt.

JOC 1997,62,(19):6582

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Phase II trials of TB drug through open source drug discovery programme to begin soon

 phase 2, Uncategorized  Comments Off on Phase II trials of TB drug through open source drug discovery programme to begin soon
Jul 222013
 

File:PA 824.svg

PA 824

The search for a new tuberculosis drug after many decades and first time through a unique model of open drug discovery programme may finally bear fruits in near future, with India all set for the launch of the phase II clinical trial of the drug candidate.

The drug, coming through the Open Source Drug Discovery (OSDD) programme by Council of Scientific and Industrial Research (CSIR), will go for the clinical trials on drug-resistant TB patients in India very soon. The process of filing for permission from the Drug Controller General of India (DCGI) is on and public sector LRS Hospital for Respiratory and Infectious Diseases, New Delhi, has been selected for trials. This phase II trials will involve around 250-300 patients, sources said.

The drug candidate, Pa824, was synthesised in India long ago. After a series of ownership changes, the molecule was licensed to CSIR for further development now.

http://www.pharmabiz.com/NewsDetails.aspx?aid=76568&sid=1

Tuberculosis (TB) is one of the leading infectious diseases in the world, with approximately one-third of the world’s population harboring the causative agent, Mycobacterium tuberculosis (Mtb). Though previously a disease associated with aristocratic societies, TB is now predominantly a third-world disease, particularly affecting Asian communities and sub-Saharan Africa. Mtb isolates are increasingly resistant to drug therapies: multidrug-resistant TB (MDR TB) or more severely, extensively drug-resistant TB (XDR TB). As a consequence of these emerging strains, it is becoming increasingly apparent that novel drugs are necessary to combat Mtb infections.

PA 824 is an experimental anti-tuberculosis drug.[1][2] The bicyclic nitroimidazole like molecule PA-824 has got a very complex mechanism of action active against both replicating and hypoxic, non-replicating Mycobacterium tuberculosis.Microarray analysis of the mode of action of PA-824 showed a puzzling mixed effect both on genes responsive to both cell wall inhibition (like isoniazid) and respiratory poisoning (like cyanide). The aerobic killing mechanism of this drug appears to involve inhibition of cell wall mycolic acid biosynthesis through an as yet unknown molecular mechanism.The respiratory poisoning through nitric oxide release seemed to be a crucial element of anaerobic activity by PA-824. The effect of PA-824 on the respiratory complex under hypoxic non-replicating conditions was also manifested in a rapid drop in intracellular ATP levels, again similar to that observed by cyanide treatment.[3]PA-824 recently was shown to be safe, well tolerated, and efficacious at doses of 100–200 mg daily in a dose-ranging study among drug-sensitive, sputum smear–positive, adult pulmonary TB patients [4]

  1.  Ginsberg AM, Laurenzi MW, Rouse DJ, Whitney KD, Spigelman MK (September 2009). “Safety, tolerability, and pharmacokinetics of PA-824 in healthy subjects”Antimicrob. Agents Chemother. 53 (9): 3720–5.doi:10.1128/AAC.00106-09PMC 2737845PMID 19528280.
  2.  Stover CK, Warrener P, VanDevanter DR, et al (2000). “A small-molecule nitroimidazopyran drug candidate for the treatment of tuberculosis”. Nature 405 (6789): 962–6. doi:10.1038/35016103PMID 10879539.
  3. Manjunatha U, Boshoff IM Helena, Barry CE (May-Jun 2009). “The mechanism of action of PA-824”Commun Integr Biol. 2 (3): 215–218. PMC 2717523.
  4. http://www.pipelinereport.org/browse/tb-treatments/pa-824

QSAR modeling of the nitroimidazole PA-824. Shown are two hydrogen bond acceptors (green), one hydrogen bond donor (purple), and one hydrophobe (aqua). Credit: NIAID

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