反应详情

A mixture of 3-amino-2-thiophenecarboxylic acid (8 g, 49 mmol), ethyl 4-fluorobenzoylacetate (9.6 g, 49 mmol), and p-toluenesulfonic acid monohydrate (0.2 g, 1 mmol) in toluene (100 mL) is refluxed for 20 hours in a flask equipped with a Dean-Stark water trap. The mixture is cooled to room temperature and the precipitate filtered and washed with diethyl ether. The solid is dissolved in diphenyl ether (80 mL) and heated at 240° C. for 2 hours. The reaction solution is then cooled to room temperature, diethyl ether added and the precipitate filtered and washed with diethyl ether to give 5-(4-fluorophenyl)-thieno[3,2-b]pyridin-7-ol as brown crystalline needles, m.p. 316-318° C.

1. temperatureis refluxed for 20 hours in a flask
2. filtrationthe precipitate filtered
3. washwashed with diethyl ether
4. dissolutionThe solid is dissolved in diphenyl ether (80 mL)
5. temperatureheated at 240° C. for 2 hours
6. temperatureThe reaction solution is then cooled to room temperature
7. additiondiethyl ether added
8. filtrationthe precipitate filtered
9. washwashed with diethyl ether