Trifluoroacetic acid → (2S,4S)-4-azido-pyrrolidine-2-carboxylic acid methyl ester trifluoro-acetate salt

Participants

Reaction Steps

To a solution of (2S,4S)-4-azido-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (7.8 g, 28.8 mmol) in methylene chloride (30 mL) was added a mixture of trifluoroacetic acid and methylene chloride (1:5, 20 mL) and the reaction mixture was stirred at room temp. for 16 h. The reaction mixture was concentrated under reduced pressure to give (2S,4S)-4-azido-pyrrolidine-2-carboxylic acid methyl ester trifluoroacetate salt (9.6 g, crude) as a light brown oil. The compound was used in the next step without further purification. MS calcd. for C6H11N4O2 [(M+H)+] 171.0, obsd. 171.2.

Provenance & Evidence