Method for obtaining derivatives of [ [(pyridil substituted)methyl]thio]benzomidazol

The method for obtaining derivatives of [[(pyridil substituted)methyl]thio]benzomidazol (I), where each of R 1 , R 3 and R 4 , independently of each other, is hydrogen, an alkyl, alkoxy or fluorinated alkoxy of 1 to 6 carbon atoms, and R 2 is nitro, halogen, alkoxy or halogenated alkoxy of 1 to 6 carbon atoms, or a group -OR-(CH 2 ) n -OR 8 , where n is an integer between 1 and 6 and R 8 represents hydrogen or an alkyl group with 1 to 6 carbon atoms, which involves (a) reacting an N-oxide of a methylpyridine with an anhydride of activated carboxylic acid or of sulfonic acid, and (b) reacting the intermediate formed in stage (a) with a corresponding mercaptobenzomidazol. The compounds (I) are useful in the synthesis of derivatives of [[(pyridil substituted)methyl]sulfinyl]benzomidazol, such as omeprazol, lansoprazol, rabeprazol or pantoprazol. 1