反应详情

温度

0 °C

NaOH (2.01 g, 50.5 mmol) was dissolved in water (30 mL) at 0° C. A sol. of hydroxylamine hydrochloride (1.75 g, 25.2 mmol) in water (30 mL) was added. Ethyl 2-methyl-4,4,4-trifluoroacetoacetate (5.00 g, 25.2 mmol) was added, and the mixture was stirred at 0° C. for 90 min. Aq. cone. HCl (26 mL) was added and the mixture was stirred for 1 h at 4° C. The mixture was filtered, and the precipitate was dried under high vacuum at 40° C. This delivered a first crop of title compound (0.56 g, 12%). The filtrate was extracted with EtOAc (2×). The combined org. extracts were dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Drying the residue under high vacuum yielded a second crop of the title compound (1.81 g, 38%; total: 2.37 g, 50%). LC-MS: tR=0.58, ES+: not visible.

1. stirringthe mixture was stirred for 1 h at 4° C
2. filtrationThe mixture was filtered
3. customthe precipitate was dried under high vacuum at 40° C
4. extractionThe filtrate was extracted with EtOAc (2×)
5. dry with materialextracts were dried over MgSO4
6. filtrationfiltered
7. customthe solvents were removed under reduced pressure
8. customDrying the residue under high vacuum