Hydrochloric Acid → Dimethyl 4-fluoro-2-nitrophenylmalonate

Participants

Reaction Steps

185 g potassium-tert-butoxide are added to a solution of 188 ml of dimethyl malonate in 970 ml N-methylpyrrolidone while cooling with ice and the mixture is stirred for 2 hours. Over a period of 30 minutes 150 ml of 2,5-difluoronitrobenzene are added dropwise to the slurry formed and then the mixture is stirred for 6 hours at 85° C. The mixture is poured onto 4 litres of ice water and 250 ml of concentrated hydrochloric acid and extracted with 2 litres of ethyl acetate. The organic phase is dried with sodium sulphate and evaporated down. The oily residue is stirred twice with water and then taken up in 600 ml of ethyl acetate. The solution is dried with sodium sulphate and evaporated to dryness. The crude product crystallised is recrystallised from 600 ml of ethyl acetate/hexane=2:8 and dried.

Provenance & Evidence