反应详情

TFA (3.6 mL) was added to a stirred solution of 4-{2-[(biphenyl-4-carbonyl)-amino]-acetyl}-piperazine-1-carboxylicacid tert-butyl ester (1.7 g, 4.01 mmol) in DCM (18 mL) at 0-4° C. and the resulting mixture was stirred at this temperature for 3 hrs. The reaction mixture was concentrated to afford 1.67 g (94.8% yield) of biphenyl-4-carboxylic acid (2-oxo-2-piperazin-1-yl-ethyl)-amide TFA salt. LC-MS purity: 85.4%,

1. concentrationThe reaction mixture was concentrated