p-Toluenesulfonic acid → Denagliptin Tosylate

Participants

Reaction Conditions

Reaction Steps

A 10L reactor equipped with overhead stirring was charged with a slurry of tert-Butyl {(1S)-1-[bis(4-fluorophenyl)methyl]-2-[(2S,4S)-2-cyano-4-fluoro-1-pyrrolidinyl]-2-oxoethyl}carbamate (500 g, 1 wt, 1 eq) in ethanol (3.5L, 7 vol). To this solution was added para-toluenesulfonic acid (403g, 0.806 wt, 2 eq). This solution was heated to 60° C., and was allowed to stir at this temperature for 12 hours. The reaction mixture was cooled to 5° C. and was stirred at this temperature for 30 minutes. The solids were collected by filtration, washed with ethanol (2×1 L), and dried to constant weight in a 50° C. vacuum oven. Yield: 70-80% over 2 steps.

Provenance & Evidence