Triethylamine → N,N-dihexyl-1-benzyl-1,2-dihydro-2-oxoquinoxaline-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

In 30 ml of tetrahydrofuran were dissolved 0.50 g of 1-benzyl-1,2-dihydro-2-oxoquinoxaline-3-carboxylic acid and 0.87 ml of triethylamine, and after cooling to —40° C., 0.19 ml of ethyl chlorocarbonate was added dropwise over 5 minutes. After stirring at −40° C. for 10 minutes, 0.46 ml of dihexylamine was added dropwise over 5 minutes. After stirring at −40° C. for an hour, the temperature was raised to room temperature over an hour, followed by stirring at room temperature overnight. The reaction mixture was concentrated under reduced pressure, and the residue, after addition of ethyl acetate, was washed with water, 1N hydrochloric acid, a saturated aqueous sodium bicarbonate solution and a saturated aqueous sodium chloride solution, and dried over anhydrous sodium sulfate. After removal of the drying agent by filtration, the filtrate was concentrated under reduced pressure. The residue was purified by chromatography (silica gel; Wakogel C200 (manufactured by Wako Pure Chemicals), developing solvent; chloroform) and recrystallized from hexane to give 0.53 g of N,N-dihexyl-1-benzyl-1,2-dihydro-2-oxoquinoxaline-3-carboxamide.

Provenance & Evidence