Sodium Hydroxide → Lansoprazole

Participants

Reaction Conditions

Reaction Steps

40 g (0.1077 mole) 2-[[[3-methyl-4-(2,2,2-trifluoro-ethoxy)-2-pyridinyl]methyl]thio]-1H-benzimidazole hydrate was suspended in 240 ml of ethanol and 0.264 g (1.077 mmole) vanadium(V) oxytriisopropoxide dissolved in 1 ml of ethanol were added at room temperature (20-25° C.). The suspension was cooled to 10-12° C. and 12.14 g (0.129 mole) hydrogen peroxide urea adduct were added. The reaction was carried out at 10-15° C. for two hours and then at 5-10° C. until the reaction was completed. At the end of the reaction (3-6 hours, depending upon the temperature), 6 g of sodium thiosulphate pentahydrate in a solution of 40 ml water and 120 ml ethanol were added at 5-10° C., the mixture was stirred for one hour at 10-15° C. and 0.5 ml of 30% aqueous solution of sodium hydroxide were added to achieve a pH of about 10. The suspension was heated to 50-55° C., hot filtered and then gradually cooled to room temperature in one hour and then to 5-10° C. in half to one hour and agitated at that temperature for another one hour. The product was filtered off to obtain 48 g of wet lansoprazole.

Provenance & Evidence