反应详情

温度

100 °C

A mixture of 3-[3-bromo-phenyl]-[1,2,4]thiadiazole-5-carboxylic acid ethyl ester (16.8 g, 53.5 mmol), sodium hydroxide (2.4 g, 58.8 mmol), distilled water (120 mL), and ethanol (20 mL) was heated to 100° C. for 2 hours. The reaction mixture was cooled to room temperature. Concentrated hydrochloric acid (5.1 mL) was added, and the reaction mixture re-heated to 100° C. for 3 hours. The solution was cooled to room temperature and extracted with diethyl ether (3×150 mL). The combined organic layers were washed with distilled water (3×100 mL), and dried over MgSO4. After the solvent was removed, 3-[3-bromo-phenyl]-[1,2,4]thiadiazole was obtained as white needles (12.7 g, 99%): mp 69-71° C.; 1H-NMR (CDCl3) δ 9.89 (s, 1H), 8.52 (t, 1H, J=1.8 Hz), 8.28 (dt, 1H, J=5.2, 1.3 Hz), 7.61 (dq, 1H, J=4.9, 1.1 Hz), 7.35 (t, 1H, J=7.9 Hz); MS ((+)APCI) [M+H]+@ m/z 241/243. Anal. Calc. For C8H5BrN2S: C, 39.85; H, 2.09; N, 11.62. Found: C, 39.82; H, 2.43; N, 11.33.

1. distillationdistilled water (120 mL), and ethanol (20 mL)
2. temperatureThe reaction mixture was cooled to room temperature
3. additionConcentrated hydrochloric acid (5.1 mL) was added
4. temperaturethe reaction mixture re-heated to 100° C. for 3 hours
5. temperatureThe solution was cooled to room temperature
6. extractionextracted with diethyl ether (3×150 mL)
7. washThe combined organic layers were washed with distilled water (3×100 mL)
8. dry with materialdried over MgSO4
9. customAfter the solvent was removed