1,1'-Carbonyldiimidazole → Ethyl 3-(7-fluoro-4-oxo-4,5-dihydroimidazo[1,5-a]quinoxalin-1-yl)propanoate

Participants

Reaction Steps

Ethyl 3-[1-(2-amino-4-fluorophenyl)-1H-imidazol-2-yl]-propanoate as synthesized in Production Example 92, 94 mg, 1,1′-carbonyldiimidazole 83 mg and 1,2-dichlorobenzene 1 mL were mixed and heated under reflux for 0.5 hour. Further 1 mL of 1,2-dichlorobenzene was added and the heating under reflux was continued for further 3 hours. Allowing the reaction liquid to cool off, the precipitate was recovered by filtration, and washed with diethyl ether and ethyl acetate, by the order stated. The resulting crystals were dissolved in a liquid mixture of tetrahydrofuran and methanol, and the insoluble matter was separated by filtration. Distilling the solvent off under reduced pressure, 70 mg of the title compound was obtained.

Provenance & Evidence