Triethylamine → (S)-4-(Benzyloxycarbonyl)-1-(diphenylcarbamoyl)piperazine-2-carboxylic acid

Participants

Reaction Steps

A solution of 1.03 g (3.90 mmole) of (S)-4-(benzyloxycarbonyl)piperazine-2-carboxylic acid (from Step A) in 12 ml. of DMF was treated with 0.788 g (7.79 mmole) of triethylamine at 25° C. With stirring 0.901 g (3.89 mmole) of diphenylcarbamoyl chloride was added in portions over 2 hours. After 16 hours the mixture was concentrated in vacuo to an orange oil which was chromatographed over an 88×2.5 cm LH 20 column with 11 ml. fractions of methanol. Fractions 35-43 were combined and concentrated to 1.136 g (64%) of pale yellow oil which contained a major spot by TLC (80:18:2 chloroform methanol ammonia water, Rf =0.45).

Provenance & Evidence