反应详情

温度

100 °C

A mixture of 4-amino-3-hydroxybenzoic acid (250 mg, 1.63 mmol) and trimethyl orthoformate (500 μL, 4.57 mmol) are heated in an oil bath at 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 1,3-benzoxazole-6-carboxylic acid as a brown solid (237 mg, 89%): 1H NMR (DMSO-d6) δ 13.2, 8.9, 8.3, 8.0, 7.9.

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