反应详情

To a solution of benzo[d]oxazole-5-carboxylic acid (7.8 g, 1.0 eq), N,O-dimethylhydroxylamine hydrochloride (7.0 g, 1.5 eq), HOBt (7.76 g, 1.2 eq) and EDCI (11 g, 1.2 eq) in 100 mL CH2Cl2 was added Et3N (19 g, 4.0 eq) dropwise at 0° C. The mixture was then stirred at rt overnight, concentrated, and purified by column chromatography with petroleum ether:EtOAc=1:1 to give the desired product (6.0 g, 51%). 1H NMR (400 MHz, CDCl3) δ 8.18 (s, 1H), 8.16 (1H), 7.80 (d, J=8.4 Hz, 1H), 7.62 (d, J=8.0 Hz, 1H), 3.56 (s, 3H), 3.41 (s, 3H).

1. concentrationconcentrated
2. custompurified by column chromatography with petroleum ether