反应详情

温度

25 °C

To a solution of 38.8 g. (0.2 mole) of 4-bromo-3-methoxyisothiazole prepared as in Example 15 in 80 ml. of dimethylformamide was added 54 g. (0.6 mole) of cuprous cyanide. The mixture was stirred and heated at reflux for 1 hour. Then the reaction mixture was cooled to 25° C., and 40 g. (0.81 mole) of sodium cyanide in 120 ml. of water was added in portions. The mixture exothermed to 60°-70° C. and was allowed again to cool to 25° C. The reaction solution was then extracted thoroughly with ether. The ether extracts were washed with 10% sodium cyanide solution and then water. After drying over anhydrous magnesium sulfate and evaporation 23.4 g. (83%) of 4-cyano-3-methoxyisothiazole was obtained as a white solid, m.p. 60°-62° C. after crystallization from ligroin (90°-120°).

1. temperatureheated
2. temperatureat reflux for 1 hour
3. customexothermed to 60°-70° C.
4. temperatureto cool to 25° C
5. extractionThe reaction solution was then extracted thoroughly with ether
6. washThe ether extracts were washed with 10% sodium cyanide solution
7. dry with materialAfter drying over anhydrous magnesium sulfate and evaporation 23.4 g