Method for preparing 2- (2-pyridylmethylsulphinyl) benzimidazoles
AssigneesIndustrial Technology Research Institute, Syn-Tech Chem & Pharm Co., Ltd.
InventorChih-Hung Chen
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Abstract
The present invention provides a method for preparing an antiulcer agent, 2-(2-pyridylmethylsulphinyl)benzimidazoles, such as Omeprazole, Lansoprazole and Pantoprazole, which includes oxidizing an intermediate having a linkage of methylthio group (—CH2S—) to methylsulfinyl (—CH2S(O)—) in the presence of an oxidation catalyst of acetyl acetonate of molybdenium (II) [(CH3C(O)CH2C(O)CH2)2Mo].
Claims16
A method for preparing 2-(2-pyridylmethylsulphinyl) benzimidazole having the following formula [A], which comprises undergoing an oxidation reaction of an intermediate having the following formula [B] in a solvent and in the presence of a catalyst and an oxidant to form the compound [A]:
- wherein R1 in [A] and [B] is hydrogen, halogen, C1–C6 alkyl, C1–C6 alkoxy, halogenated C1–C6 alkyl, or halogenated C1–C6 alkoxy;
- R2 and R3 independently are hydrogen, halogen, C1–C6 alkyl, C1–C6 alkoxy, halogenated C1–C6 alkyl, or halogenated C1–C6 alkoxy;
- and R4 is hydrogen, C1–C6 alkyl, or halogenated C1–C6 alkyl;
- characterized in that said catalyst is acetyl acetonate of molybdenium (II).
Dependencies are inferred from the claim text.