937369-77-2

58333-72-5

937369-77-2

Ethyl 5-phenyl-2-thiazolecarboxylate (4.5 g, 19.3 mmol) was used as a raw material, which was dissolved in methanol (80 mL), followed by the addition of aqueous sodium hydroxide (150 mL, 4 M). The reaction mixture was stirred at room temperature for 2 h. After completion of the reaction, methanol was removed by distillation under reduced pressure. The remaining aqueous phase was acidified to pH=3 with aqueous hydrochloric acid (1 M) and then extracted with ethyl acetate. The organic phase was dried with anhydrous sodium sulfate, filtered and concentrated to give the crude product. The crude product was purified by silica gel column chromatography, eluting with appropriate eluents to give the final target compound 5-phenylthiazole-2-carboxylic acid (3.3 g, 82.3% yield). Mass spectrometry analysis (ESI) showed m/z of 206.0 [M+1].