Potassium Hydroxide → 7-[4-(4-Morpholinyl)phenyl]-1-benzothiophene-2-carboxylic acid

A solution of 330 mg (0.77 mmol) of methyl 7-[4-(4-morpholinyl)phenyl]-1-benzothiophene-2-carboxylate (Example 19A) in 6 ml of a 1:1 mixture of methanol and 2N potassium hydroxide solution is stirred at room temperature for 2 h and at 50° C. for 1 h. The reaction mixture is concentrated in vacuo and, after addition of water, acidified with conc. hydrochloric acid. The resulting precipitate is filtered off with suction, washed twice with water and dried under high vacuum. 292 mg of crude product are obtained and reacted without further purification.