反应详情

A mixture of 3,5-dimethyl-4-methoxybenzoic acid ethyl ester (PREPARATION 2, 10.5 g) and aqueous sodium hydroxide (20%, 100 ml) is refluxed for 18 hours. The solution is cooled and acidified with hydrochloric acid (12N, pH 2). The acidified solution is extracted with chloroform (3 X). The combined extracts are dried over sodium sulfate and concentrated under reduced pressure to give a solid which is recrystallized from ether/pet ether mixture to give the title compound, mp 189°-191°.

1. temperatureis refluxed for 18 hours
2. temperatureThe solution is cooled
3. extractionThe acidified solution is extracted with chloroform (3 X)
4. dry with materialThe combined extracts are dried over sodium sulfate
5. concentrationconcentrated under reduced pressure
6. customto give a solid which
7. customis recrystallized from ether/pet ether mixture