m-Chloroperbenzoic acid → HCID 178488147, compound

Participants

Reaction Steps

125 g of crude omeprazole, obtained by oxidation of 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]thio]-1H-benzimidazole with 3-chloroperoxybenzoic acid, were dissolved while stirring in a mixture of 100 ml of 40% of aqueous methylamine and 125 ml of acetone at room temperature. To this clear solution was added 2000 ml of acetone, the combined solution was stirred for 1 hour at room temperature, and thereafter cooled to a temperature in the range of −10 to −15° C. The product formed was filtered off and then washed with acetone. The crystals formed still wet were suspended in 400 ml of water at room temperature and thereafter stirred vigorously for 1 hour while cooling to a temperature not exceeding 20° C. with an ULTRA-TURRAX® mixer (type 18/10, Janke&Kunkel). The product obtained—omeprazole form C was filtered off, washed with water, and dried in vacuo at room temperature to constant weight.

Provenance & Evidence