Reacción #93537

Ecuación de reacción

sodium borohydride

p-chlorophenacyl bromide

ammonium acetate

potassium

monomethyl malonate

→

title compound

Rendimiento 71.0%

β-(p-chlorophenyl)-γ-butyrolactone

Rendimiento 71.0%

Disolventes

acetic acid

dimethyl sulfoxide

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturacooling over one hour
2. 2
   workup.WAITto stand at room temperature for one hour
3. 3
   Temperaturathe mixture was heated under reflex at 125°-130° C. for 3 hours
4. 4
   OtroAfter completion of the reaction
5. 5
   Otrothe black precipitate thus separated
6. 6
   Filtraciónwas collected by filtration
7. 7
   workup.DISTILLATIONsubjected to distillation under reduced pressure

Procedimiento

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%).

Fuente