Dimethylamine, hydrochloride → 4-Benzyl-N,N-dimethyl-3,4-dihydro-3-oxo-2-quinoxalinecarboxamide

Participants

Reaction Steps

Dimethylamine hydrochloride (0.57 g), WSC (1.33 g) and HOBt (0.86 g) were added to a mixed solution of 4-benzyl-3,4-dihydro-3-oxo-2-quinoxalinecarboxylic acid (1.5 g) in THF (30 ml) and acetonitrile (30 ml), to which was added dropwise triethylamine (2.3 ml) under ice-cooling. The reaction mixture was stirred at room temperature for 15 hours. The precipitated insoluble substances were removed by filtration and the filtrate was concentrated. Water was added to the precipitate, which was extracted with ethyl acetate. The ethyl acetate layer was washed with 1N hydrochloric acid, water, a saturated aqueous sodium hydrogencarbonate solution, and a saturated aqueous sodium chloride solution, then dried and concentrated. The residue was recrystallized from ethyl acetate-hexane to obtain the entitled compound (1.47 g).

Provenance & Evidence