Ethyl 2-bromo-4-methyl-1,3-thiazole-5-carboxylate

7210-76-6

22900-83-0

General procedure for the synthesis of ethyl 2-bromo-4-methyl-1,3-thiazole-5-carboxylate from ethyl 2-amino-4-methylthiazole-5-carboxylate: first, 2-methyl-1-nitro-propyl-propene (28.2 mL, 2.1 eq.) was dissolved in acetonitrile (700 mL) and the solution was cooled to 0 °C. Subsequently, bromo-trimethyl-silane (32 mL , 2.1 eq.). The reaction mixture was maintained at 0°C. Next, ethyl 2-amino-4-methyl-thiazole-5-carboxylate (18.6 g, 0.1 mol) was added to an acetonitrile/ethyl acetate (75/25) solution. After the dropwise addition was completed, the reaction mixture continued to be kept at 0°C. The mixture was warmed to room temperature and stirred for 24 hours. After completion of the reaction, the solvent was removed by evaporation and water was added. The product was extracted with ethyl acetate, the organic phase was dried with anhydrous sodium sulfate, filtered and concentrated. Finally, purification by fast chromatography using dichloromethane as eluent gave ethyl 2-bromo-4-methyl-1,3-thiazole-5-carboxylate as a yellow solid (21.74 g, 87 mmol, 87% yield); GC/MS analysis: [M+] C7H8BrNO2S 250.