440100-94-7

51640-52-9

440100-94-7

General procedure for the synthesis of 2-bromo-5-cyano thiazole from 2-amino-5-cyano thiazole: (1) Preparation of 2-bromo-5-cyano thiazole: 2-amino-5-cyano thiazole (875 mg, 7.00 mmol) prepared according to the method described in the unexamined disclosure of the Japanese Patent (KOKAI) No. 9-169,748, was dissolved in 47% hydrobromic acid (14 mL) and a water in a mixed solution (14 mL). An aqueous solution of sodium nitrite (580 mg, 8.40 mmol) was added slowly and dropwise (7 mL) to this solution under ice bath cooling conditions. The reaction mixture was stirred at the same temperature for 5 min and then warmed up to 50 °C and continued stirring for 6 h. The reaction was carried out at the same temperature. After completion of the reaction, ethyl acetate was added to the mixture for extraction, and the organic layer was washed sequentially with water, saturated aqueous sodium bicarbonate solution and saturated saline. The organic layer was dried over anhydrous magnesium sulfate and the solvent was concentrated under reduced pressure to give 2-bromo-5-cyanothiazole (1.05 g, 5.56 mmol) as an orange solid in 79% yield.1H NMR (DMSO-d6) δ (ppm): 8.57 (1H, s).