Trifluoroacetic acid methylene chloride → (2S,4S)-4-(9H-Fluoren-9-ylmethoxycarbonylamino)-pyrrolidine-2-carboxylic acid benzyl ester trifluoroacetate

Participants

Reaction Steps

A mixture of 20 mL TFA/DCM (1:1) at 0° C. was added to (2S,4S)-4-(9H-fluoren-9-ylmethoxycarbonylamino)-pyrrolidine-1,2-dicarboxylic acid 2-benzyl ester 1-tert-butyl ester (0.92 g, 0.17 mmol) at 0° C., the cooling bath was removed and the mixture stirred for 2 h. The mixture was concentrated and triturated with diethyl ether to give (2S,4S)-4-(9H-Fluoren-9-ylmethoxycarbonylamino)-pyrrolidine-2-carboxylic acid benzyl ester trifluoroacetate (0.94 g) as a white solid.

Provenance & Evidence