反应详情

A solution of 5-chloro-2-hydroxybenzoic acid (102 g) and hexamethylenetetramine (166 g) in trifluoroacetic acid is heated overnight. Dilute hydrochloric acid is added to the mixture and the mixture is heated. After cooling, the precipitates are collected by filtration, whereby 5-chloro-3-formyl-2-hydroxybenzoic acid (96.9 g) is obtained. m.p. 218° C.

1. temperaturethe mixture is heated
2. temperatureAfter cooling
3. filtrationthe precipitates are collected by filtration