Water → Rabeprazole

Participants

Reaction Steps

2-[{4-(3-Methoxypropoxy)-3-methylpyridin-2-yl}methylthio]-1H-benzimidazole (25.0 g (72.8 mmol)) was dissolved in dichloromethane and cooled. Then, mcpba (70.2% purity; 8.95 g (36.4 mmol)) was added gradually so that the internal temperature did not exceed −15° C. 10% Aqueous sodium hydroxide solution (70.8 ml) was then added, and after stirring and still standing the water layer was separated. The separated water layer was washed with dichloromethane (48 ml) twice. After addition of a 2N-ammonium acetate aqueous solution, the water layer was extracted with dichloromethane (48 ml) twice. The dichloromethane layer was washed with water (48 ml) twice, concentrated under a reduced pressure, crystallized with dichloromethane (28 ml) and ethyl acetate (184 ml), and filtered to obtain 2-[{4-(3-methoxypropoxy)-3-methylpyridin-2-yl}methylsulfinyl]-1H-benzimidazole (10.9 g) (HPLC purity 99.7%, yield 41.7%).

Provenance & Evidence