反应详情

To a solution of dimethyl-p-tolyl phosphane (25 g, 0.165 mol) (1a) in diclholoromethane (DCM) (50 mL) was added an aqueous solution of hydrogen peroxide (10%, 60 mL, 0.176 mol) in drops. This is an exothermic reaction so the flask was cooled in ice water during the addition. After the addition the reaction was allowed to stir at rt overnight until the HPLC showed no starting material (18 h). From the resulting reaction mixture the organic phase was separated and the aqueous phase was extracted with additional dichloromethane (3—60 mL) until the aqueous layer showed little or no evidence of product by HPLC. The combined organics were washed with a solution of sodium bisulfite (10 mL) followed by water (10 mL) and dried over Na2SO4 and concentrated on a rotary evaporator. The desired product was purified by Crystallization from ethyl acetate/hexane (18.8 g). m.p. 90–92° C., 1H NMR (300 MHz, CDCl3) δ (ppm)) 1.469 (d, J=13 Hz, 6H), 2.16 g (s, 3H), 7.04 (d, J=5.5 Hz, 2H), 7.38 (m, 2H). 3P NMR (121 MHz, CDCl3) δ 34.327.

1. customan exothermic reaction so the flask
2. additionAfter the addition the reaction
3. customno starting material (18 h)
4. customFrom the resulting reaction mixture the organic phase
5. customwas separated
6. extractionthe aqueous phase was extracted with additional dichloromethane (3—60 mL) until the aqueous layer
7. washThe combined organics were washed with a solution of sodium bisulfite (10 mL)
8. dry with materialdried over Na2SO4
9. concentrationconcentrated on a rotary evaporator
10. customThe desired product was purified by Crystallization from ethyl acetate/hexane (18.8 g)