反应详情

温度

0 °C

To a solution of tetrahydrofuran (100 ml) and triphenylphosphine (3.56 g, 13.6 mmol) at room temperature is added lithium (0.100 g, 14.5 mmol). The reaction mixture is stirred at room temperature for 2 hours at which time the lithium has dissolved. The bright red solution is cooled to 0° C., and 3-(chloromethyl)pyrazole hydrochloride (0.960 g, 6.8 mmol) is added at once. The ice bath is removed and the reaction solution is allowed to stir an additional 2 hours. Degassed ethanol (40 ml) is added to the reaction mixture followed by diethyl ether (100 ml). The organic phase is separated and the aqueous phase extracted with diethyl ether (2×25 ml). The organic phases are combined and dried over magnesium sulfate, filtered and concentrated. The crude residue is purified by chromatography (SiO2, 50% ethyl acetate/petroleum ether) to give purified 3-(diphenylphosphinomethyl)pyrazole as a cloudy white oil in 77% yield (2.81 g, 10.6 mmol). This material is characterized as follows: 1H NMR (CDCl3, 500 MHz) δ7.43 (m,4H), 7.41 (d, J=2.0 Hz, 1H), 7.34 (m, 6H), 5.99 (d, J=2.0 Hz, 1H), 3.47 (s, 2H); 13C{1H} NMR (CDCl3, 125 MHz) δ138.16 (d, 14.3 Hz), 132.97 (d, J=18.6 Hz), 129.11, 128.73 (d, J=6.6 Hz), 105.18 (d, J=5.1 Hz), 27.14 (d, J=6.2 Hz) MS m/z 265.9, 182.9 (M—C4H3N2).

1. dissolutionhas dissolved
2. customThe ice bath is removed
3. additionDegassed ethanol (40 ml) is added to the reaction mixture
4. customThe organic phase is separated
5. extractionthe aqueous phase extracted with diethyl ether (2×25 ml)
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. customThe crude residue is purified by chromatography (SiO2, 50% ethyl acetate/petroleum ether)
10. customto give
11. custompurified 3-(diphenylphosphinomethyl)pyrazole as a cloudy white oil in 77% yield (2.81 g, 10.6 mmol)