反应详情

To ethyl 2-ethyl-4-hydroxycyclopentanecarboxylate (3.52 g, 18.9 mmol, Preparation #P.1) in DCM (21 mL) at about 0° C. was added aqueous potassium hydroxide (50%, 21 mL, 189 mmol), tetrabutylammonium hydrogen sulfate (0.64 g, 1.891 mmol) and 2,2,2-trichloroacetonitrile (9.5 mL, 95 mmol). The reaction mixture was allowed to warm to ambient temperature and stirred at ambient temperature for about 14 h. The layers were separated and the aqueous layer was extracted with DCM (4×60 mL). The combined organic layers were washed with water (2×50 mL), brine (60 mL), dried over anhydrous MgSO4, filtered and concd under reduced pressure. The material was purified by silica gel chromatography eluting with a gradient of 15-50% EtOAc in heptane to afford ethyl 2-ethyl-4-(2,2,2-trichloro-1-iminoethoxy)cyclopentanecarboxylate (2.80 g, 45%) as a colorless oil: LC/MS (Table 1, Method b) Rt=2.91 min; MS m/z: 330 (M+H)+.

1. customThe layers were separated
2. extractionthe aqueous layer was extracted with DCM (4×60 mL)
3. washThe combined organic layers were washed with water (2×50 mL), brine (60 mL)
4. dry with materialdried over anhydrous MgSO4
5. filtrationfiltered
6. customThe material was purified by silica gel chromatography
7. washeluting with a gradient of 15-50% EtOAc in heptane