Lawesson's reagent → (2S,4R)-1-(2-isobutyl-5-methyl-2H-pyrazol-3-yl)-4-(2-trifluoromethyl-benzenesulfonyl)-pyrrolidine-2-carboxylic acid methyl ester

Participants

Reaction Steps

In analogy to the procedure described in example 308d, a mixture of (2S,4R)-1-(3-oxo-butyryl)-4-(2-trifluoromethyl-benzenesulfonyl)-pyrrolidine-2-carboxylic acid methyl ester (example 192 f) and of (2R,4R)-1-(3-oxo-butyryl)-4-(2-trifluoromethyl-benzenesulfonyl)-pyrrolidine-2-carboxylic acid methyl ester was reacted with Lawesson's reagent (CAS Reg. No. 19172-47-5) and (2-methylpropyl)-hydrazine 4-methylbenzenesulfonate (CAS Reg. No. 112306-59-9) to give a mixture of the title compound and (2R,4R)-1-(2-isobutyl-5-methyl-2H-pyrazol-3-yl)-4-(2-trifluoromethyl-benzenesulfonyl)-pyrrolidine-2-carboxylic acid methyl ester as yellow solid. MS (ESI): m/z=474.2 [M+H]+.

Provenance & Evidence