反应详情

5,5,5-trifluoro-4,4-dimethyl-3-oxopentanenitrile (524 mg, 2.9 mmol) described in Example 259A Steps 1 and 2 was taken in water (2.9 ml), treated with sodium hydroxide (240 mg, 6 mmol) and the resulting solution stirred at rt for 15 min. After this time hydroxylamine hydrochloride (213 mg, 3.07 mmol) was added and the mixture was heated at 80° C. for 2.5 h. After cooling to rt chloroform was added (20 mL) and the organic phase separated. The water phase was back extracted three times, the organics were combined, dried over MgSO4 and concentrated to afford 3-(1,1,1-trifluoro-2-methylpropan-2-yl)isoxazol-5-amine (150 mg, 27%) as a solid, which was used without further purification. 1H NMR (300 MHz, CDCl3) δ 5.19 (s, 1H), 4.50 (brs, 2H), 1.54 (s, 6H); LC-MS (ESI) m/z 195 (M+H)+.

1. temperaturethe mixture was heated at 80° C. for 2.5 h
2. additionwas added (20 mL)
3. customthe organic phase separated
4. extractionThe water phase was back extracted three times
5. dry with materialdried over MgSO4
6. concentrationconcentrated