Hydrochloric Acid → HCID 59198862, compound

Participants

Reaction Steps

Ethyl 1-cyclohexyl-4-oxo-4,5-dihydroimidazo[1,5-a]-quinoxaline-8-carboxyate as synthesized in Example 102, 503 mg was suspended in 9 mL of tetrahydrofuran, and into the suspension 1.7 mL of 3M methylmagnesium bromide solution in diethyl ether was dropped, followed by 23 hours' stirring at room temperature under nitrogen atmosphere. The reaction liquid was poured into water, and of which pH was adjusted to 9 with diluted hydrochloric acid and saturated aqueous sodium hydrogencarbonate solution. The precipitated crystals were recovered by filtration and washed with water. The crude product was heat-suspended in acetone and purified. The crude product was alkali-treated and thereafter its pH was adjusted to 10 by addition of diluted hydrochoric acid (i.e. the carboxyic acid was dissolved in water). Thus precipitated crystals were recovered by filtration, washed with water, heat-suspended in 2-propanol and purified. Further recrystallizing the same from N,N-dimethylformamide-water mixed solvent, 133 mg of the title compound was obtained.

Provenance & Evidence