HCID 18965166, compound → HCID 54561088, compound

Participants

Reaction Conditions

Reaction Steps

A 2.13 g (3 96 mmole) portion of (S)-4-(benzyloxycarbonyl)-1-[N-(3-bromophenyl-N-phenylcarbamoyl]piperazine-2-carboxylic acid (from Step B) was dissolved in 40 ml of 30% HBr in acetic acid. After stirring for 1 hour at 25° C., the solution was flushed with nitrogen to remove the excess of HBr. Concentration in vacuo gave an oily residue which was partitioned between 100 ml of methylene chloride and 100 ml of water. The stirred slurry was neutralized to pH 7 with 10% NaOH solution. After a brief stirring the entire mixture was filtered to collect 1.50 g (3.71 mmole, 94%) of white solid which was homogeneous by TLC (5:1:1:1 ethyl acetate-n-butyl alcohol-ethyl acetate-water Rf =0.33).

Provenance & Evidence