反应详情

温度

100 °C

A mixture of 4-amino-3-hydroxybenzoic acid (500 mg, 3.7 mmol) and trimethyl orthoacetate (1.0 mL, 7.9 mmol) is heated in an oil bath to 100° C. for 2 h. The mixture is cooled to rt and diluted with MeOH. The resulting solution is filtered through a pad of Celite, and the filtrate is concentrated in vacuo to give 2-methyl-1,3-benzoxazole-6-carboxylic acid as an off-white solid (266 mg, 46%): 1H NMR (DMSO-d6) δ 13.1, 8.2, 8.0, 7.7, 2.7.

1. temperatureThe mixture is cooled to rt
2. filtrationThe resulting solution is filtered through a pad of Celite
3. concentrationthe filtrate is concentrated in vacuo