反应详情

Tetramethylethylenediamine (TMEDA) (49 g, 0.42 mole), under nitrogen, is treated with n-butyl lithium (168 mL of 2.57 N in hexanes, 0.42 mole) at 0° C., stirred for 0.5 hour at room temperature, treated dropwise with N-(trimethylsilyl)-4-methoxy-o-toluidine (40.0 g, 0.19 mole), heated at reflux temperature for 4 hours, cooled to -78° C., diluted with dry cyclohexane, treated dropwise with ethyl trifluoroacetate (45 g, 0.23 mole), stirred at -78° C. for 0.5 hour, warmed to room temperature and quenched with saturated NH4Cl solution. The mixture is extracted with diethyl ether. The combined extracts are washed sequentially with saturated NH4Cl and brine, dried over Na2SO4 and concentrated in vacuo to give a brown oil residue. The oil is chromatographed (silica gel/10% ethyl acetate in hexanes) to give the title product as white needles, 5.0 g (12% yield), mp 60° C. (after recrystallization from pentane), identified by IR, 1HNMR, 13CNMR, 19FNMR and mass spectral analyses.

1. temperatureheated
2. temperatureat reflux temperature for 4 hours
3. temperaturecooled to -78° C.
4. stirringstirred at -78° C. for 0.5 hour
5. temperaturewarmed to room temperature
6. customquenched with saturated NH4Cl solution
7. extractionThe mixture is extracted with diethyl ether
8. washThe combined extracts are washed sequentially with saturated NH4Cl and brine
9. dry with materialdried over Na2SO4
10. concentrationconcentrated in vacuo
11. customto give a brown oil residue
12. customThe oil is chromatographed (silica gel/10% ethyl acetate in hexanes)
13. customto give
14. customthe title product as white needles, 5.0 g (12% yield), mp 60° C. (after recrystallization from pentane)