Sodium hydride → Diallyl 2-(4-cyanobutyl)malonate

Participants

Reaction Conditions

Reaction Steps

21.71 g (542.9 mmol; 60% pure) of sodium hydride are added in portions to a solution of 100 g (542.9 mmol) of diallyl malonate in 700 ml of dry dioxane at 0° C. After gas evolution ceases, the reaction mixture is warmed to 40° C. and stirred for 1 hour. Then 43.98 g (271.5 mmol) of 5-bromovaleronitrile in 350 ml of dry dioxane are added dropwise, and the mixture is stirred at 110° C. for 12 hours. After the reaction is complete, the mixture is cooled to room temperature, mixed with 400 ml of saturated ammonium chloride solution and extracted with ethyl acetate. After phase separation, the aqueous phase is extracted three further times with 250 ml of ethyl acetate each time. After the organic phases have been combined they are washed with saturated sodium chloride solution and dried over sodium sulfate, and then the solvent is stripped off in vacuo. Excess diallyl malonate is subsequently removed by high vacuum distillation (boiling point: 57° C.; 0.074 mbar). The resulting distillation residue is purified by flash chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 2:1). 105 g (233 mmol, approx. 60% purity, 43% of theory) of the title compound are obtained, which compound is reacted without further purification in the subsequent stage. A small amount is purified by preparative HPLC for analytical characterization.

Provenance & Evidence