Diisopropylcarbodiimide → 4-[4-[[(Phenylmethoxy)amino]carbonyl]phenyl]-1-piperazinecarboxylic acid, 1,1-dimethylethyl ester

Participants

Reaction Steps

A mixture of 4-(4-carboxyphenyl)-1-piperazinecarboxylic acid, 1-(1,1-dimethylethyl) ester (0.032 mol), O-(phenylmethyl)-hydroxylamine hydrochloride (0.064 mol), DMAP (0.03 mol) in DCM p.a. (250 ml) and TEA (14 ml) was stirred at room temperature. DIC (0.064 mol) was added. The reaction mixture was stirred at room temperature for 8 hours, then washed with water, HCl (0.5N) and water. The separated organic layer was dried (MgSO4), filtered and the solvent was evaporated. The residue was purified by column chromatography over silica gel (eluent: DCM/MeOH 98/2). The desired fractions were collected and the solvent was evaporated, yielding 13.7 g of 4-[4-[[(phenylmethoxy)amino]carbonyl]phenyl]-1-piperazinecarboxylic acid, 1,1-dimethylethyl ester (interm. 4).

Provenance & Evidence