915030-08-9

The general procedure for the synthesis of 2-(trifluoromethyl)-1,3-thiazole-4-carboxylic acid from ethyl 2-(trifluoromethyl)thiazole-4-carboxylate was as follows: ethyl 2-(trifluoromethyl)thiazole-4-carboxylate (400 mg, 1.176 mmol) was dissolved in a solvent mixture of THF/methanol (9:1, v/v), and a 1 M aqueous lithium hydroxide (3.55 mL, 3.55 mmol). The reaction mixture was stirred at room temperature for 1 h, followed by adjusting the pH with dilute hydrochloric acid to 2. The reaction mixture was extracted three times with ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate and concentrated to dryness under reduced pressure. The product yield was 93% and mass spectrometric detection showed m/z [M+H]+ of 197.1.

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