O-Phenylenediamine → 4-[3-(2-Amino-phenylcarbamoyl)-phenyl]-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

A solution of 4-(3-carboxy-phenyl)-piperazine-1-carboxylic acid tert-butyl ester (5.80 g, 18.95 mmol) and 1,1-carbonyldiimidazole (CDI) (3.07 g, 18.95 mmol) in acetonitrile (120 mL) was stirred for 3 h at room temperature, then 1,2-phenylenediamine (2.25 g, 20.85 mmol) was added. The resulting suspension was refluxed for 3 h, then cooled to room temperature and the solvent removed under reduced pressure. The resulting residue was diluted with dichlomethane (200 mL), washed with water (3×40 mL) and the organic layer dried over Na2SO4, filtered and evaporated under reduced pressure. The crude product was recrystallized from EtOAc to obtain 2.99 g (40%) of the title compound.

Provenance & Evidence