Hydrochloric Acid → 2-Phenylbenzo[d]oxazole-7-carboxamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-phenylbenzo[d]oxazole-7-carboxylic acid in DMF (15 mL) was added HOBt (148 mg, 1.1 mmol), NH4Cl (54 mg, 1.0 mmol), DIPEA (387 mg, 3.0 mmol) and EDCI (211 mg, 1.1 mmol). The mixture was stirred at 25° C. for 10 hr. To the resulting mixture, water (10 mL) and aqueous hydrochloric acid (1 N) was added to pH=3, then extracted with ethyl acetate (100 mL×4). The organic phase was washed with saturated sodium bicarbonate solution and brine, concentrated and dried in vacuum. The crude product was purified by pre-HPLC to obtain 2-phenylbenzo[d]oxazole-7-carboxamide as a white solid (40 mg, yield 16% for 2 steps). 1H-NMR (400 MHz, DMSO-d6) δ 7.48-7.52 (t, J=8 Hz, 1H), 7.62-7.68 (m, 3H), 7.81-7.83 (dd, J1=8 Hz, J2=1 Hz, 1H), 7.88-7.92 (d, J=8 Hz, 2H), 7.96-7.99 (dd, J1=8 Hz, J2=1 Hz, 1H), 8.30-8.33 (dd, J1=8 Hz, J2=2 Hz, 2H); LC-MS (ESI) m/z 239 [M+1]+.

Provenance & Evidence