Water → HCID 178515622, compound

Participants

Reaction Steps

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 with a Dean-Stark water trap to remove produced water. After cooling to room temperature, the precipitate is filtered and washed with diethyl ether. The solid is dissolved in diphenyl ether (80 mL) and heated at 220° C. for 2 hours. The reaction solution is then cooled to room temperature, diethyl ether is added, and the precipitate is filtered and washed with diethyl ether to give 5-(4-fluorophenyl)-thieno[3,2-b]pyridin-7-ol (2 g, 17% yield) as brown crystalline needles, m.p. 316-318°C.

Provenance & Evidence