반응 #50928

반응 방정식

4-amino-3-hydroxybenzoic acid

trimethyl orthoformate

MeOH

→

1,3-benzoxazole-5-carboxylic acid

수율 27.0%

반응 조건

후처리

1. 1
   온도The mixture is cooled to rt
2. 2
   여과The resulting solution is filtered through a pad of Celite
3. 3
   농축the filtrate is concentrated in vacuo

실험 절차

A mixture of 4-amino-3-hydroxybenzoic acid (1.0 g, 6.5 mmol) and trimethyl orthoformate (2.0 mL, 18.3 mmol) is heated in an oil bath at 100° C. for 30 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-5-carboxylic acid as a brown solid (290 mg, 27%): 1H NMR (DMSO-d6) δ 13.0, 8.9, 8.3, 8.1, 7.9.

출처