反应详情

To a solution of 5.465 g (20 mmol) 2-(2-methoxy-4-trifluoromethyl-phenyl)-4,4-dimethyl-4,5-dihydro-oxazole in 60 ml dry THF were added at <−60° C. 11.0 ml (22 mmol) lithium diisopropylamide solution 2M in THF/heptanes/ethylbenzene and the mixture stirred for 1.5 h at <−60° C. To the resulting dark brown solution were added 2.5 ml (40 mmol) iodomethane drop wise over 10 min (exothermal, Ti<−48° C.). The resulting light brown solution was stirred at <−50° C. for 2.5 h then quenched with sat. aq. NH4Cl solution and extracted three times with tert-butyl methyl ether. The combined organic phases were washed 3× with brine, dried over Na2SO4, filtered and evaporated: 7.002 g yellow solid: which was purified by flash-chromatography on silica gel with heptane and 5 to 10% AcOEt over 25 min and heptane/AcOEt 90:10 for 20 min to provide the title compound as a light yellow oil. MS (m/e): 288.12 (M+H+).

1. custom(exothermal, Ti<−48° C.)
2. customthen quenched with sat. aq. NH4Cl solution
3. extractionextracted three times with tert-butyl methyl ether
4. washThe combined organic phases were washed 3× with brine
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. customevaporated
8. custom7.002 g yellow solid: which was purified by flash-chromatography on silica gel with heptane and 5 to 10% AcOEt over 25 min