Lansoprazole → 3-{2-[3-Methyl-4-(2,2,2-trifluoro-ethoxy)-pyridin-2-yl-methanesulfinyl]-benzimidazole-1-sulfonyl}-4-methylbenzoic acid 2-(toluene-4-sulfonyl)ethyl ester

Participants

Reaction Steps

To a heterogeneous mixture of 2-[3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl-methanesulfinyl]-1H-benzimidazole (LANSOPRAZOLE, 700 mg, 1.89 mmol), 3 mL of Et3N, and about 1 g of NaHCO3 in CH2Cl2 (15 mL) was added the sulfonyl chloride (Intermediate 49, 1.03 g, 2.47 mmol, 1.3 eq) in CH2Cl2 (5 mL) at room temperature, and then the mixture was stirred for 2 h. Thereafter water was added, the mixture was extracted with CH2Cl2, and the organic layers were dried, and concentrated. The resulting residual oil was purified by column chromatography (CH2Cl2 to 1% MeOH in CH2Cl2) to yield 1.1 g (78%) of 3-{2-[3-methyl-4-(2,2,2-trifluoro-ethoxy)-pyridin-2-yl-methanesulfinyl]-benzimidazole-1-sulfonyl}-4-methylbenzoic acid 2-(toluene-4-sulfonyl)ethyl ester (Intermediate 52) as a yellow foam.

Provenance & Evidence