DR ANTHONY MELVIN CRASTO Ph.D

DR ANTHONY MELVIN CRASTO, Worlddrugtracker, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his PhD from ICT ,1991, Mumbai, India, in Organic chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with AFRICURE PHARMA as ADVISOR earlier GLENMARK LS Research centre as consultant,Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Prior to joining Glenmark, he worked with major multinationals like Hoechst Marion Roussel, now sSanofi, Searle India ltd, now Rpg lifesciences, etc. he is now helping millions, has million hits on google on all organic chemistry websites. His New Drug Approvals, Green Chemistry International, Eurekamoments in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 32 year tenure, good knowledge of IPM, GMP, Regulatory aspects, he has several international drug patents published worldwide . He gas good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, polymorphism etc He suffered a paralytic stroke in dec 2007 and is bound to a wheelchair, this seems to have injected feul in him to help chemists around the world, he is more active than before and is pushing boundaries, he has one lakh connections on all networking sites, He makes himself available to all, contact him on +91 9323115463, [email protected]

Cholecystokinin-2/gastrin antagonists: 5-hydroxy-5-aryl-pyrrol-2-ones as anti-inflammatory analgesics for the treatment of inflammatory bowel disease

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Mar 132017

Cholecystokinin-2/gastrin antagonists: 5-hydroxy-5-aryl-pyrrol-2-ones as anti-inflammatory analgesics for the treatment of inflammatory bowel disease

Med. Chem. Commun., 2017, Advance Article
DOI: 10.1039/C6MD00707D, Research Article

E. Lattmann, J. Sattayasai, R. Narayanan, N. Ngoc, D. Burrell, P. N. Balaram, T. Palizdar, P. Lattmann
Arylated 5-hydroxy-pyrrol-2-ones were prepared in 2 synthetic steps from mucochloric acid and optimised as CCK₂-selective ligands using a range of assays.

Cholecystokinin-2/gastrin antagonists: 5-hydroxy-5-aryl-pyrrol-2-ones as anti-inflammatory analgesics for the treatment of inflammatory bowel disease

E. Lattmann,*^a J. Sattayasai,^b R. Narayanan,^c N. Ngoc,^a D. Burrell,^a P. N. Balaram,^d T. Palizdar^a and P. Lattmann^d

*Corresponding authors

^aSchool of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
E-mail: [email protected]

^bDepartment of Pharmacology, Faculty of Medicine, Khon Kaen University, 40002 Khon Kaen, Thailand

^cDepartment of Medicine, University of Tennessee Health Science Center, Memphis, USA

^dPNB Vesper Life Science PVT, Cochin, India

Med. Chem. Commun., 2017, Advance Article

DOI: 10.1039/C6MD00707D

Arylated 5-hydroxy-pyrrol-2-ones were prepared in 2 synthetic steps from mucochloric acid and optimised as CCK₂-selective ligands using radiolabelled binding assays. CCK antagonism was confirmed for the ligands in isolated tissue preparations. DSS (dextran sulfate sodium)-induced inflammation was analysed for derivative 7 and PNB-001 with L-365,260 as a standard. The IC₅₀ of PNB-001 was determined to be 10 nM. Subsequent in vivo evaluation confirmed anti-inflammatory activity with respect to IBD assays. The best molecule, PNB-001, showed analgesic activity in the formalin test and in the hotplate assay, in which the analgesic effect of 1.5 mg kg⁻¹ PNB-001 was equivalent to 40 mg kg⁻¹ tramadol. The CCK₂-selective antagonist PNB-001 protected rats against indomethacin-induced ulceration at similar doses. The GI protection activity was found to be more potent than that of the 10 mg kg⁻¹ dose of prednisolone, which served as a standard.

General Method: The relevant amine (2.5 times excess) was added to a solution of lactone A – E (0.7 mol) in ether (10 ml) and stirred on ice for 30 minutes, allowing to warm up to RT over the time. The resultant mixture was poured into 5 ml water and separated by separating funnel. The mixture was washed with water three times. The organic layer was dried over magnesium sulphate and the solvent was removed under vacuum. All compounds gave an oily solid which were passed through a column (80% ether, 20% petrol ether). The resulting fractions were dried from excess solvent under vacuum to yield crystals. 4-Chloro-1-cyclopropyl-5-hydroxy-5-phenyl-1,5-dihydro-pyrrol-2-one 1 Yield = 83 %; mp: 177-179 oC;

MS (APCI(+)): 193/195 (M+1), 250/252 (M+) m/z

1H NMR (CDCl3) 250 MHz:  = 7.41 (m, 5H), 6.09 (s, 1H), 3.50 (m, 1H), 2.18 (m, 1H), 0.95-1.04 & 0.38-0.69 (m, 4H);

13C NMR (CDCl3) 167.4, 154.8, 135.2, 129.2, 128.8, 126.1, 122.2, 93.5, 22.6 , 3.8, 5.1;

IR (KBr-disc)  max: 3416, 3260, 3105, 3011, 2363, 2338, 1671, 1602, 1490, 1450, 1409, 1369, 1256, 1144, 1032, 939, 833, 752, 702 cm-1 .

/////////////////Cholecystokinin-2/gastrin antagonists, 5-hydroxy-5-aryl-pyrrol-2-ones, anti-inflammatory analgesics, inflammatory bowel disease

Award for me, 100 Most Impactful Health care Leaders, Global listing

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Feb 142017

str6

At award function for my award “100 Most Impactful Health care Leaders Global listing”, conferred on me at Taj lands end, Mumbai, India on 14 Feb 2014 by World Health Wellness congress and awards

tert-butyl(3aR,6aS)-5-oxohexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate

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Feb 092017

Abstract Image

tert-butyl(3aR,6aS)-5-oxohexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate

tert-Butyl (3aR,6aS)-5-Oxohexahydrocyclopenta[c]pyrrole-2(1H)-carboxylate (1)

pure compound 1 (1.051 kg, 67%) as a white solid. Mp: 70–71 °C (uncorrected); [α]²⁵_D +0.40° (c 1.00 CHCl₃); % purity: 98.5% (HPLC);

¹H NMR (CDCl₃, 400 MHz) δ: 1.46 (s, 9H), 2.15 (dd, J₁ = 4.8 Hz, J₂ = 19.6 Hz, 2H), 2.47 (dd, J₁ = 7.4 Hz, J₂ = 19.6 Hz, 2H), 2.93 (bs, 2H), 3.16–3.28 (m, 2H), 3.65–3.67 (m, 2H).;

¹³C NMR (CDCl₃, 100 MHz) δ: 38.49, 39.36, 42.32, 50.51, 50.77, 79.49, 154.39, 217.65; IR (KBr): ν = 638, 771, 877, 1118, 1166, 1247, 1367, 1402, 1691, 1741, 2877, 2910, 2958, 2976, 3005 cm^–1;

TOFMS: [C₁₂H₁₉NO₃ + H⁺]: calculated 226.1438, found 152.0663 (M-OtBu)⁺ (100%), 170.0755 (M-tBu + H)⁺ (40%), 248.1166 (M + Na)⁺ (5%).

Anal. Calcd for C₁₂H₁₉NO₃: C, 63.98; H, 8.50; N, 6.22. Found: C, 63.89; H, 8.27; N, 5.97.

HPLC conditions were as follows for compound ; Agilent 1100 series, column: YMC J’SPHERE C18 (150 mm X 4.6 mm) 4µm with mobile phases A (0.05% TFA in water) and B (acetonitrile). Detection was at 210 nm, flow was set at 1.0 mL/min, and the temperature was 30 °C (Run time: 45 min). Gradient: 0 min, A = 90%, B = 10%; 5.0 min, A = 90%, B = 10%; 25 min, A = 0%, B = 100%; 30 min, A = 0%, B = 100%, 35 min, A = 90%, B = 10%; 45 min, A = 90%, B = 10%.

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00399

http://pubs.acs.org/doi/full/10.1021/acs.oprd.6b00399

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(3R)-4-[2-chloro-6-[[(R)-methylsulfinyl]methyl]pyrimidin-4-yl]-3-methyl-morpholine

spectroscopy Comments Off

Feb 092017

(3R)-4-[2-chloro-6-[[(R)-methylsulfinyl]methyl]pyrimidin-4-yl]-3-methyl-morpholine

Synthesis of (3R)-4-[2-chloro-6-[[(R)-methylsulfinyl]methyl]pyrimidin-4-yl]-3-methyl-morpholine (10)

off-white solid (53.9 kg, 68.3% yield). 1H NMR (400 MHz, DMSO-d6, δ): 1.20 (d, J = 6.8 Hz, 3 H), 2.52 (m, 1 H), 2.63 (s, 3 H), 3.21 (m, 1 H), 3.44 (m, 1 H), 3.58 (dd, J = 11.6, 3.1 Hz, 1 H), 3.72 (d, J = 11.5 Hz, 1 H), 3.92 (m, 3 H), 4.07 (d, J = 12.4 Hz, 1 H), 6.80 (s, 1 H); Assay (HPLC) 99%; Assay (QNMR) 100%; Chiral purity (HPLC) (R,R)-diastereoisomer 99.6%, (R,S)-diastereoisomer 0.4%.

A Baeyer–Villiger monooxygenase enzyme has been used to manufacture a chiral sulfoxide drug intermediate on a kilogram scale. This paper describes the evolution of the biocatalytic manufacturing process from the initial enzyme screen, development of a kilo lab process, to further optimization for plant scale manufacture. Efficient gas–liquid mass transfer of oxygen is key to obtaining a high yield.

Development and Scale-up of a Biocatalytic Process To Form a Chiral Sulfoxide

William R. F. Goundry^*

, Bradley Adams, Helen Benson, Julie Demeritt†∥, Steven McKown, Keith Mulholland, Amy Robertson, Paul Siedlecki, Paula Tomlin, and Kevin Vare

The Departments of Pharmaceutical Sciences and Pharmaceutical Technology and Development, AstraZeneca, Silk Road Business Park, Macclesfield, Cheshire SK10 2NA, United Kingdom

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00391

Publication Date (Web): January 4, 2017

*Tel: +44 (0)1625-519149. E-mail: [email protected].

http://pubs.acs.org/doi/full/10.1021/acs.oprd.6b00391

Examples of biologically active molecules containing a sulfoxide or sulfoximine: esomeprazole (3), aprikalim (4), oxisurane (5), OPC-29030 (6), ZD3638 (7), buthionine sulfoximine (8), and AZD6738 (9).

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article is a compilation for educational purposes only.

P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

(±)-trans-ethyl 2-(3,4-difluorophenyl)Cyclopropanecarboxylate

spectroscopy Comments Off

Feb 092017

(±)-trans-ethyl 2-(3,4-difluorophenyl)Cyclopropanecarboxylate

C12H12F2O2

GC-MS (EI) m/z: [M]+ calc. for C12H12F2O2 + : 226.08; found: 226.08.

δH (400 MHz, CDCl3): 1.25 (1H, ddd, 3 J 8.4 Hz, 3 J 6.4 Hz, 2 J 4.5 Hz , 3-H); 1.28 (3H, t 3 J 6.4 Hz CH3Ethyl) 1.57-1.62 (2H, m, 3 J 9.2 Hz, 3 J 5.2 Hz, 2 J 4.5 Hz, 3-H + H2O), 1.84 (1H, ddd, 3 J 8.5 Hz, 3 J 5.3 Hz, 3 J 4.3 Hz , 2-H), 2.47 (1H, ddd, 3 J 9.5 Hz, 3 J 6.4 Hz, 3 J 4.2 Hz , 1-H), 4.17 (2H, q, 3 J 6.3 Hz, CH2Ethyl) 6.81-6.87 (1H, m, 3 J 8.5 Hz, 4 J 7.6 Hz, 4 J 2.4 Hz, 6-H’ ), 6.88 (1H, ddd, 3 J 11.5 Hz, 4 J 7.6 Hz, 4 J 2.2 Hz, 2-H’) 7.06 (1H, dt, 3 J 10.3 Hz, 3 J 8.2 Hz. 5-H’).

δc (400 MHz, CDCl3): 14.27 (CH3Ethyl), 16.84 (3-C) 24.04 (1-C), 25.14 (d, 4 J 1.4, 2-C), 60.71 (CH2Ethyl), 114.74 (d, 2 J 19 Hz, 2-C’), 117.09 (d, 2 J 18 Hz, 5-C’), 122.25 (dd, 3 J 6.1 Hz, 4 J 3.4 Hz, 6- C’), 137.06 (dd, 3 J 6.1 Hz, 4 J 3.4 Hz, 1- C’), 149.2 (dd, 1 J 248 Hz, 2 J 13 Hz, 4-C’) 151.32 (dd, 1 J 249 Hz, 2 J 12.5 Hz, 3-C’) 172.87 (Ccarbonyl).

[ ] 20 a D = -381.9 (c 1.0 in EtOH) for (1R,2R)-3, ee = 95%

In this study a batch reactor process is compared to a flow chemistry approach for lipase-catalyzed resolution of the cyclopropanecarboxylate ester (±)-3. (1R,2R)-3 is a precursor of the amine (1R,2S)-2 which is a key building block of the API ticagrelor. For both flow and batch operation, the biocatalyst could be recycled several times, whereas in the case of the flow process the reaction time was significantly reduced.

Comparison of a Batch and Flow Approach for the Lipase-Catalyzed Resolution of a Cyclopropanecarboxylate Ester, A Key Building Block for the Synthesis of Ticagrelor

Katharina G. Hugentobler^†, Marcello Rasparini^‡, Lisa A. Thompson^§, Katherine E. Jolley^§, A. John Blacker^§, and Nicholas J. Turner^*^†

^† School of Chemistry, University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester M1 7DN, United Kingdom

^‡ Chemessentia, SRL – Via G. Bovio, 6-28100 Novara, Italy

^§ Institute of Process Research and Development, School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, United Kingdom

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00346

Publication Date (Web): December 22, 2016

*E-mail: [email protected].

http://pubs.acs.org/doi/suppl/10.1021/acs.oprd.6b00346

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article is a compilation for educational purposes only.

P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

tert-Butyl 3a,4,7,7a-Tetrahydro-1H-isoindole-2(3H)-carboxylate

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Feb 042017

tert-Butyl 3a,4,7,7a-Tetrahydro-1H-isoindole-2(3H)-carboxylate

tert-Butyl 3a,4,7,7a-Tetrahydro-1H-isoindole-2(3H)-carboxylate

as a brown oil. % Purity: 93.72% (GC);

¹H NMR (CDCl₃, 400 MHz) δ: 1.47 (s, 9H), 1.89–194 (m, 2H), 2.20–2.33 (m, 4H), 3.08 (dd, J₁ = 6.2 Hz, J₂= 10.2 Hz, 1H), 3.17 (dd, J₁ = 4.8 Hz, J₂ = 10.4 Hz, 1H), 3.37–3.43 (m, 2H), 5.65 (s, 2H);

¹³C NMR (CDCl₃, 100 MHz) δ: 24.63, 24.68, 28.49, 33.35, 34.23, 50.86, 50.92, 78.88, 124.19, 124.50, 155.22;

IR (CHCl₃): ν = 756, 1128, 1170, 1217, 1411, 1685, 2937, 2978, 3009 cm^–1;

TOFMS: [C₁₃H₂₁NO₂ + H⁺]: calculated 224.1645, found 168.0958 (M-tBu + H)⁺ (100%), 246.1382 (M + Na)⁺ (5%).

GC conditions were as follows for compound 4; Agilent GC-FID 7890A, column: ZB-5MSi (30 m X 0.32 mm, 0.25 µm) with injector temperature 250 ºC and detector temperature 280 ºC, diluent was Methanol, Oven temperature was at 70 ºC isocratic for 3 min. then raised up to 250 ºC @ 20 ºC/min then 15 min. hold.

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00399

http://pubs.acs.org/doi/full/10.1021/acs.oprd.6b00399

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2,2′-(1-(tert-Butoxycarbonyl)pyrrolidine-3,4-diyl)diacetic Acid

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Feb 012017

2,2′-(1-(tert-Butoxycarbonyl)pyrrolidine-3,4-diyl)diacetic Acid

as a white solid. Mp: 162–163 °C, % purity: 94.09% (HPLC);

¹H NMR (DMSO-d₆, 400 MHz) δ: 1.38 (s, 9H), 2.10–2.18 (m, 2H), 2.28–2.32 (m, 2H), 2.49–2.50 (m, 2H, merged with DMSO peak), 2.97–3.03 (m, 2H), 3.33–3.40 (m, 2H), 12.23 (bs, 2H); ¹H NMR (CD₃OD, 400 MHz) δ: 1.46 (s, 9H), 2.26 (ddd, J₁ = 2.8 Hz, J₂ = 9.2 Hz, J₃ = 16.0 Hz, 2H), 2.43 (dd, J₁ = 5.2 Hz, J₂ = 16.0 Hz, 2H), 2.69 (m, 2H), 3.16 (dd, J₁ = 5.2 Hz, J₂ = 10.8 Hz, 2H), 3.49–3.54 (m, 2H);

¹³C NMR (DMSO-d₆, 100 MHz) δ: 28.49, 32.97, 36.49, 37.31, 50.10, 50.20, 78.67, 154.05, 173.96;

IR (KBr): ν = 871, 933, 1143, 1166, 1292, 1411, 1689, 1708, 2881, 2929, 2980, 3001 cm^–1;

TOFMS: [C₁₃H₂₁NO₆ – H⁺]: calculated 286.1296, found 286.1031(100%).

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00399

http://pubs.acs.org/doi/full/10.1021/acs.oprd.6b00399

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Dimethyl 4,4′-(Benzylazanediyl)(2E,2′E)-bis(but-2-enoate)

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Jan 312017

Dimethyl 4,4′-(Benzylazanediyl)(2E,2′E)-bis(but-2-enoate)

IR (CHCl₃): ν = 758, 1215, 1278, 1437, 1660, 1720, 2806, 2953, 3020, 3421 cm^–1;

¹³C NMR (CDCl₃, 100 MHz) δ: 51.53, 53.42, 58.37, 122.66, 127.28, 128.41, 128.55, 128.76, 138.24, 145.84, 166.58;

¹H NMR (CDCl₃, 400 MHz) δ: 3.23 (dd, J₁ = 1.6 Hz, J₂ = 6.0 Hz, 4H), 3.62 (s, 2H), 3.75 (s, 6H), 6.07 (dt, J₁ = 1.6 Hz, J₂ = 16.0 Hz, 2H), 6.97 (dt, J₁ = 6.0 Hz, J₂ = 16.0 Hz, 2H), 7.25–7.34 (m, 5H-merged with CDCl₃ proton);

TOFMS: [C₁₇H₂₁NO₄ + H⁺]: calculated 304.1543, found 304.1703(100%).

UPLC conditions were as follows for compound 11; Acquity Waters, column: BEH C18 (2.1 mm X 100 mm) 1.7 µm with mobile phases A (0.05% TFA in water) and B (acetonitrile). Detection was at 220 nm, flow was set at 0.4 mL/min, and the temperature was 30 °C (Run time: 9 min). Gradient: 0 min, A = 90%, B = 10%; 0.5 min, A = 90%, B = 10%; 6.0 min, A = 0%, B = 100%; 7.5 min, A = 0%, B = 100%; 7.6 min, A = 90%, B = 10%; 9.0 min, A = 90%, B = 10%.

Dimethyl 4,4′-(Benzylazanediyl)(2E,2′E)-bis(but-2-enoate) (11)

as a yellow oil. % purity: 93.4% (UPLC);

¹³C NMR (CDCl₃, 100 MHz) δ: 51.53, 53.42, 58.37, 122.66, 127.28, 128.41, 128.55, 128.76, 138.24, 145.84, 166.58;

IR (CHCl₃): ν = 758, 1215, 1278, 1437, 1660, 1720, 2806, 2953, 3020, 3421 cm^–1;

TOFMS: [C₁₇H₂₁NO₄ + H⁺]: calculated 304.1543, found 304.1703(100%).

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00399

http://pubs.acs.org/doi/full/10.1021/acs.oprd.6b00399

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1-Bromo-4-fluoro-2-((2-iodobenzyl)oxy)benzene

Uncategorized Comments Off

Jan 252017

1-Bromo-4-fluoro-2-((2-iodobenzyl)oxy)benzene

CAS 1161931-51-6

Mp 89.8–92.3 °C.

IR (neat, ATR): 3072 (w), 1482 (s), 1451 (s), 1294 (s), 1294 (s) cm^–1.

¹H NMR (399 MHz, DMSO-d₆) δ 5.12 (s, 2H), 6.81 (td, J = 8.49, 2.77 Hz, 1H), 7.14 (td, J = 7.64, 1.65 Hz, 1H), 7.18 (dd, J = 10.90, 2.82 Hz, 1H), 7.46 (td, J = 7.52, 0.92 Hz, 1H), 7.60 (dd, J = 7.64, 1.41 Hz, 1H), 7.62 (dd, J = 8.66, 6.23 Hz, 1H), 7.92 (dd, J = 7.83, 0.83 Hz, 1H).

¹³C NMR (100 MHz, DMSO-d₆) δ 74.5, 99.2, 102.4 (d, J = 27.1 Hz), 105.8 (d, J = 3.4 Hz), 108.9 (d, J = 22.5 Hz), 128.5, 129.8, 130.3, 133.6 (d, J = 9.9 Hz), 138.0, 139.2, 155.4 (d, J = 10.7 Hz), 162.2 (d, J = 244.3 Hz).

GCMS: m/z [M]⁺ calcd for C₁₃H₉BrFIO: 405.88600; found: 405.88620.

1H AND 13C NMR PREDICT

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00368

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article is a compilation for educational purposes only.

P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent

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Brc2ccc(F)cc2OCc1ccccc1I

One-Pot Reductive Cyclisations of Nitroanilines to Imidazoles

spectroscopy, SYNTHESIS, Uncategorized Comments Off

Jan 252017

Hana and co-workers ( Synlett 2010, 18, 2759−2764) from Genentech have developed a single-step procedure for conversion of 2-nitro aromatic amines to benzimidazoles. Addition of ammonium chloride proved necessary as Fe powder and formic acid alone was ineffective for nitro reduction. These conditions were compatible with a variety of functional groups on the aromatic, including boronate esters. The methodology was also extended to nitro aminopyridines but failed to deliver the desired product with isoxazole or pyrazole reactants.

Mild and General One-Pot Reduction and Cyclization of Aromatic and Heteroaromatic 2-Nitroamines to Bicyclic 2H-Imidazoles

Emily J. Hanan*, Bryan K. Chan, Anthony A. Estrada, Daniel G. Shore, Joseph P. Lyssikatos

*Discovery Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA, Email: hanan.emilygene.com

E. J. Hanan, B. K. Chan, A. A. Estrada, D. G. Shore, J. P. Lyssikatos, Synlett, 2010, 2759-2764.

DOI: 10.1055/s-0030-1259007

see article for more reactions

Abstract

A one-pot procedure for the conversion of aromatic and heteroaromatic 2-nitroamines into bicyclic 2H-benzimidazoles employs formic acid, iron powder, and NH₄Cl as additive to reduce the nitro group and effect the imidazole cyclization with high-yielding conversions generally within one to two hours. The compatibility with a wide range of functional groups demonstrates the general utility of this procedure.

see article for more examples

//////////One-Pot, Reductive Cyclisations, Nitroanilines, Imidazoles

“ALL FOR DRUGS” CATERS TO EDUCATION GLOBALLY, No commercial exploits are done or advertisements added by me. This article is a compilation for educational purposes only.

P.S. : The views expressed are my personal and in no-way suggest the views of the professional body or the company that I represent