Sodium hydride → Diallyl 2-[4-(methoxycarbonyl)phenyl]ethylmalonate

Participants

Reaction Conditions

Reaction Steps

Under argon and at 0° C., 4.44 g (111.0 mmol) of sodium hydride (60% strength dispersion in mineral oil) are added a little at a time to a solution of 27.28 g (148.09 mmol) of diallyl malonate in 220 ml of anhydrous dioxane. The mixture is stirred at 40° C. for 30 min, and a solution of 18.00 g (74.04 mmol) of methyl 4-(2-bromoethyl)benzoate is then added at room temperature. The reaction mixture is then heated at 110° C. for 16 hours. After addition of 25 ml of saturated ammonium chloride solution, most of the dioxane is removed on a rotary evaporator. The residue is taken up in 200 ml of ethyl acetate and 100 ml of water. The aqueous phase is extracted with ethyl acetate. The combined organic phases are washed with saturated sodium chloride solution and dried over anhydrous magnesium sulfate. After distillative removal of a large proportion of the excess diallyl malonate, the crude product is pre-purified on 100 g of silica gel 60 (mobile phase: cyclohexane/dichloromethane 2:1, then cyclohexane/ethyl acetate 4:1). The desired product is then isolated by preparative HPLC. This gives 11.60 g (22% of theory) of a colorless oil.

Provenance & Evidence