Lansoprazole → 4-[2-{3-Methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl-methanesulfinyl}-benzimidazole-1-sulfonyl]-3-isopropyl-5-methylphenoxyacetic acid 2-(toluene-4-sulfonyl)ethyl ester

Participants

Reaction Steps

To a heterogeneous solution of 2-[3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl-methanesulfinyl]-1H-benzimidazole (LANSOPRAZOLE 1.0 g, 2.71 mmol) and 2 mL of Et3N in 20 mL of CH2Cl2 was added 4-chlorosulfonyl-3-isopropyl-5-methylphenoxyacetic acid 2-(toluene-4-sulfonyl)ethyl ester the (Intermediate 65, 1.6 g, 3.25 mmol, 1.2 eq). About 1 g of solid NaHCO3 was added after the chlorosulfonyl ester has dissolved completely in the reaction mixture. The mixture was stirred at room temperature for 2 h. Thereafter the solvent was removed by evaporation and the residual oil was purified by column chromatography (silica gel, CH2Cl2 to 1% MeOH in CH2Cl2) to give 4-[2-{3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl-methanesulfinyl}-benzimidazole-1-sulfonyl]-3-isopropyl-5-methylphenoxyacetic acid 2-(toluene-4-sulfonyl)ethyl ester (Intermediate 68, 1.76 g, 79%) as a white foam.

Provenance & Evidence