反应详情

To a mixture of cis-4-hydroxy-N-methoxy-N-methylcyclohexanecarboxamide (3.556 g, 0.0190 mol) and benzyl-2,2,2-trichloroacetimidate (4.0 mL, 0.021 mol, 1.1 eq) in cyclohexane/DCM (20 mL/10 mL) at 0° C. was added trifluoromethanesulfonic acid dropwise with stirring under nitrogen atmosphere over 30 min. There was an immediate precipitate. The mixture was stirred at room temperature for 15 h, filtered, and the filtrate washed with sodium bicarbonate solution and brine. The organic layer was concentrated and purified by silica gel column chromatography using petroleum ether/ethyl acetate (5/1) as eluent to give product as a colorless oil (5.079 g, 77%). 1H NMR (400 MHz, CDCl3) δ 7.38-7.23 (m, 5H), 4.50 (s, 2H), 3.71 (s, 3H), 3.70-3.66 (m, 1H), 3.18 (s, 3H), 2.78-2.62 (m, 1H), 2.07-1.89 (m, 4H), 1.59-1.25 (m, 4H).

1. stirringThe mixture was stirred at room temperature for 15 h
2. filtrationfiltered
3. washthe filtrate washed with sodium bicarbonate solution and brine
4. concentrationThe organic layer was concentrated
5. custompurified by silica gel column chromatography