1-Hydroxybenzotriazole → 3-[4-(2-Bromo-benzoyl)-piperazin-1-yl]-3-oxo-propionic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

HOBt (585 mg, 4.3 mmol) and DIEA (933 mg, 7.2 mmol) were added to a stirred solution of lithium tert-butoxycarbonyl-acetate (600 mg, 3.6 mmol) in DMF (6 mL). The reaction mixture was cooled to 10° C. and EDCI.HCl (830 mg, 4.3 mmol) followed by (2-bromo-phenyl)-piperazin-1-yl-methanone hydrochloride (1.3 g, 4.3 mmol) were added. The reaction mixture was stirred at room temperature overnight then diluted with water and the product extracted with ethyl acetate. The organic layer was washed with brine solution, dried over Na2SO4 and concentrated. The residue was purified by column chromatography using neutral alumina (3% methanol in chloroform) to afford 530 mg (31%) of 3-[4-(2-bromo-benzoyl)-piperazin-1-yl]-3-oxo-propionic acid tert-butyl ester. LCMS: 412.08 (M+)+, 52.6%, 1H NMR: (DMSO-d6): δ 7.7 (d, 1H), 7.5 (m, 1H), 7.4 (m, 2H), 3.7-3.4 (m, 8H), 3.2-3.1 (m, 2H), 1.4 (s, 9H).

Provenance & Evidence