acid–related diseases. During the synthesis of bulk drug of rabeprazole sodium, we have observed metabolites rabeprazole sulfide and rabeprazole sulfone and relatedsubstances rabeprazole-N-oxide, rabeprazole sulfone-N-oxide, N-aralkyl rabeprazole, chloro rabeprazole, and methoxy rabeprazole as impurities in the drugsubstance. The present work describes the synthesis and characterization of these compounds
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.