General procedure for the synthesis of 2-aminothiazole-4-ethanone from tert-butyl (4-acetylthiazol-2-yl)carbamate: Trifluoroacetic acid (5 mL) was added to the chloroform solution (10 mL) of the above-prepared acetyl compound, and the reaction was stirred at room temperature for 1.5 hours. After completion of the reaction, the reaction solution was concentrated, neutralized to neutral with saturated aqueous sodium bicarbonate solution, and the solid was collected by filtration to afford 2-aminothiazole-4-acetophenone 149 mg (yield: 59%) as a white solid. The product was characterized by 1H-NMR (CDCl3): δ 2.48 (3H, s), 7.35 (1H, s); ESI-MS (m/e): 143 [M + H]+.
