p-Chlorophenacyl bromide → 4-(p-Chlorophenyl)dihydrofuran-2(3H)-one

Participants

Reaction Steps

To 204 ml of dimethyl sulfoxide were added 40.1 g of potassium salt of monomethyl malonate (XVI) and then 50.0 g of p-chlorophenacyl bromide (XVII), and the mixture was stirred at room temperature for 30 minutes. Then, 12.9 g of ammonium acetate were added and the mixture was stirred at room temperature for 2 hours. Subsequently, 36.6 ml of acetic acid were added and 8.5 g of sodium borohydride were added under ice-cooling over one hour. The reaction mixture was allowed to stand at room temperature for one hour to reduce the double bond. After 68 ml of ice-water were added, the mixture was heated under reflex at 125°-130° C. for 3 hours to effect decarboxylation. After completion of the reaction, the reaction mixture was poured into 500 ml of ice-water, the black precipitate thus separated was collected by filtration and subjected to distillation under reduced pressure to give 29.7 g of the title compound (yield 71%).

Provenance & Evidence