Water → 3,3-Dimethyl-1,2,3,4-tetrahydroquinoxalin-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 1,2-phenylenediamine (16.96 g) in N,N-dimethylformamide (80 mL) were added successively N,N-diisopropylethylamine (36.4 mL) and ethyl α-bromoisobutyrate (39.8 g), and the mixture was heated at 110° C. for 3 days. After cooling, to the reaction mixture was added cold water and the mixture was extracted with ethyl acetate. The aqueous layer was extracted with ethyl acetate, and the combined organic layer was washed successively with an aqueous 10% HCl solution, water, an aqueous saturated sodium hydrogencarbonate solution and brine, dried over sodium sulfate and concentrated in vacuo. The resultant residue was recrystallized from dichloromethane-n-hexane to give 3,3-dimethyl-3,4-dihydroquinoxalin-2(1H)-one (15.90 g) as pale yellow crystals.

Provenance & Evidence