- Process for the preparation of pyridine-methylsulfinyl compounds
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A process for the preparation of a compound of formula (I), or a salt thereof, wherein Q is ═CR8— or ═N—; and R1-R8 are as herein defined; comprising the reaction of a compound of formula (II), or a salt thereof, wherein Q, R1-R7 are as herein defined; with a reducing agent selected from a trivalent phosphorous compound, an oxidizable solvent and a sulfonic acid chloride; and, if desired, the conversion of a compound of formula (I) to another compound of formula (I) or a salt thereof.
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Page/Page column 6
(2009/04/24)
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- Synthesis of metabolites and related substances of rabeprazole, an anti-ulcerative drug
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Rabeprazole sodium (Aciphex) is a gastric proton pump inhibitor used for the prevention and treatment of gastric acid-related diseases. During the synthesis of bulk drug of rabeprazole sodium, we have observed metabolites rabeprazole sulfide and rabeprazole sulfone and related substances rabeprazole-N-oxide, rabeprazole sulfone-N-oxide, N-aralkyl rabeprazole, chloro rabeprazole, and methoxy rabeprazole as impurities in the drug substance. The present work describes the synthesis and characterization of these compounds. Copyright Taylor & Francis Group, LLC.
- Reddy, Ganta Madhusudhan,Mukkanti, Kaga,Bhaskar, Boluggodu Vijaya,Reddy, Padi Pratap
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experimental part
p. 278 - 290
(2009/04/11)
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- A process for the preparation of pyridine-methylsulfinyl compounds
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A process for the preparation of a compound of formula (I), or a salt thereof, wherein Q is =CR8- or =N-; and R1-R8 are as herein defined; comprising the reaction of a compound of formula (II), or a salt thereof, wherein Q, R1-R7 are as herein defined; with a reducing agent selected from a trivalent phosphorous compound, an oxidizable solvent and a sulfonic acid chloride; and, if desired, the conversion of a compound of formula (I) to another compound of formula (I) or a salt thereof.
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Page/Page column 9
(2008/12/05)
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- Efficient synthesis of N-Oxide derivatives: Substituted 2-(2-(pyridyl-N-oxide)methylsulphinyl)benzimidazoles
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Different substituted 2-chloromethylpyridyl derivatives (6a-d) were oxidized with mCPBA to give the respective 2-chloromethylpyridine-N-oxide derivatives (7a-d) at low temperature, which on condensation with 2-mercapto-1H-benzimidazole (8a-c) in the presence of aprotic solvents give the 2-[[(pyridin-2-yl-1-oxide)methyl]sulfanyl]-1H-benzimidazole (9a-d) in good yield. Finally, 9a-d oxidized with mCPBA in chlorinated solvent gives a mixture of 2-[[(pyridin-2-yl-1-oxide)methyl]sulfonyl]-1H-benzimidazole (3a-d, 10%) and 2-[[(pyridin-2-yl-1-oxide) methyl]sulfinyl]-1H-benzimidazole (4a-d, 90%) derivatives. Copyright Taylor & Francis Group, LLC.
- Ray, Purna C.,Mittapelli, Vasantha,Rohatgi, Amit,Tyagi, Om Dutt
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p. 2861 - 2868
(2008/02/12)
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- Synthetic studies connected with the preparation of H+/K +-ATPase inhibitors rabeprazole and lansoprazole
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Synthesis of lansoprazole and rabeprazole using common intermediates is devised. The common intermediates, 2-[(4-nitro-3-methylpyridin-2-yl) methanesulfanyl]-1H-benzoimidazole and 2-[(4-chloro-3-methyl-pyridin-2-yl) methanesulfanyl]-1H-benzoimidazole, were prepared in several ways.
- Radl, Stanislav,Klecan, Ondrej,Havlicek, Jaroslav
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p. 1447 - 1453
(2007/10/03)
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- Identification and synthesis of potential impurities of rabeprazole sodium
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Rabeprazole sodium (1, Achiphex) is a gastric proton pump inhibitor. It causes dose-dependent inhibition of acid secretion and is useful as an anti-ulcer agent. In the process for the preparation of 1, two potential unknown impurities were identified in HPLC at levels ranging from 0.05-0.8%. Based on mass spectral data vide LC-MS, the two impurities were characterized as 2-{[(4-chloro-3-methyl-2-pyridinyl) methyl] sulfinyl}-1H-bezimidazole (2, chloro analogue of rabeprazole) and 2-[{(4-methoxy-3-methyl-2-pyridinyl)methyl} sulfinyl]-1H-benzimidazole (3, methoxy analogue of rabeprazole). The structures were unambiguously established by independently synthesizing them and co-injecting in HPLC. To our knowledge, the compounds 2 and 3 have not been reported as process impurities elsewhere.
- Pingili, R. Reddy,Jambula, M. Reddy,Ganta, M. Reddy,Ghanta, M. Reddy,Sajja,Sundaram,Boluggdu, V. Bhaskar
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p. 814 - 818
(2007/10/03)
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