反应详情

温度

60 °C

To a solution of pivaloylacetonitrile (25.03 g) and 48% sodium hydroxide (18.16 g) in water (319 ml) is added a solution of hydroxylamine sulfate (18.06 g) in water (72 ml) and the mixture is adjusted to pH 8.10±0.05 with 5% sodium hydroxide (0.38 g), stirred at 60° C. for 18 hours, mixed with 36% hydrochloric acid (26.13 g) and stirred at 70° C. for 30 minutes. Then, 36% hydrochloric acid (40.31 g) is added to the reaction mixture, which is refluxed for 40 minutes under stirring. The mixture is evaporated under atmospheric pressure to recover pinacolone (1.07 g; yield, 5.3%) and cooled to ordinary temperature. After cooling, the reaction mixture is adjusted to pH 11.8 with 48% sodium hydroxide (58.08 g) and shaken with chloroform. The chloroform layer is washed with water and concentrated under reduced pressure to give 3-amino-5-t-butylisoxazole (23.80 g). Purity, 96.6%. Yield, 84.9%. No by-product, 3-(3-t-butyl-5-isoxazolyl)amino-5-t-butylisoxazole, is detected.

1. stirringstirred at 70° C. for 30 minutes
2. temperatureis refluxed for 40 minutes
3. stirringunder stirring
4. customThe mixture is evaporated under atmospheric pressure
5. customto recover pinacolone (1.07 g; yield, 5.3%)
6. temperaturecooled to ordinary temperature
7. temperatureAfter cooling
8. stirringshaken with chloroform
9. washThe chloroform layer is washed with water
10. concentrationconcentrated under reduced pressure