反应详情

To a 0° C. solution of 100 mg (0.332 mmol) 2-(2-ethyl-6-methoxy-4-trifluoromethyl-phenyl)-4,4-dimethyl-4,5-dihydro-oxazole (obtained by reaction of 2-(2,6-dimethoxy-4-trifluoromethyl-phenyl)-4,4-dimethyl-4,5-dihydro-oxazole with ethylmagnesium bromide) in 0.6 ml tetrahydrofuran, was added drop-wise 0.332 ml (0.996 mmol) of a 3M methylmagnesium bromide solution in diethyl ether maintaining the temperature below 5° C. The mixture was allowed to warm to room temperature and stirred for 3.5 hours and then heated in a 70° C. oil bath for 4 days. The mixture was cooled in an ice bath and quenched dropwise with 3 ml saturated ammonium chloride solution. Ethyl acetate was added. The organic layer was separated and the aqueous layer was extracted three times with ethyl acetate. The combined extracts were dried over sodium sulfate, filtered and concentrated in vacuo. The crude orange oil (286 mg) was purified with flash column chromatography on silica eluting with a gradient formed from n-heptane and ethyl acetate (0 to 10%) to provide 50 mg (yield: 50.4%) of the title compound as a light yellow oil. MS (m/e): 286.2 (M+H+).

1. temperatureheated in a 70° C. oil bath for 4 days
2. temperatureThe mixture was cooled in an ice bath
3. customquenched dropwise with 3 ml saturated ammonium chloride solution
4. additionEthyl acetate was added
5. customThe organic layer was separated
6. extractionthe aqueous layer was extracted three times with ethyl acetate
7. dry with materialThe combined extracts were dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe crude orange oil (286 mg) was purified with flash column chromatography on silica eluting with a gradient
11. customformed from n-heptane and ethyl acetate (0 to 10%)