反应详情

温度

-40 °C

Cis-methyl 4-(3-ethoxy-3-oxopropanoyl)-2-(4-(trifluoromethyl)benzyl)piperidine-1-carboxylate (14.9 g, 35.87 mmol) was dissolved in MeOH (120 mL) and cooled to −40° C. Sodium hydroxide (1.495 g, 37.38 mmol) dissolved in water (14.4 mL) was added over 2 min and the resulting solution stirred at −40° C. for 20 min. Then hydroxylamine (50% by weight in water, 2.2 mL, 35.90 mmol) was added over 1 min and stirring continued between −40° C. and −45° C. for 80 min. The reaction mixture was then poured into a prewarmed (80° C.) solution of 6 M hydrogen chloride (400 mL, 2400.00 mmol) and the mixture was continued to be stirred at 80° C. for 1 h. Then cooled to room temperature. Methanol was evaporated, then water was added. Extracted three times with DCM. Combined organic layers dried over Na2SO4 and evaporated. Crude cis-methyl 4-(3-oxo-2,3-dihydroisoxazol-5-yl)-2-(4-(trifluoromethyl)benzyl)piperidine-1-carboxylate (12.88 g, 94%) was isolated. MS m/z 385 (M+H)+

1. additionwas added over 2 min
2. stirringstirring continued between −40° C. and −45° C. for 80 min
3. stirringto be stirred at 80° C. for 1 h
4. temperatureThen cooled to room temperature
5. customMethanol was evaporated
6. additionwater was added
7. extractionExtracted three times with DCM
8. dry with materialCombined organic layers dried over Na2SO4
9. customevaporated