O-Phenylenediamine → 2(1H)-Quinoxalinone, 3,4-dihydro-

Participants

Reaction Steps

To a solution of o-phenylenediamine (1.08 g, 10 mmol) in DMF (50 mL) was added Et3N (2.9 mL, 21 mmol), and ethyl 2-bromoacetate (1.2 mL, 11 mmol). The reaction mixture was stirred at room temperature for 16 h, then at 80° C. for 3 h. The DMF was evaporated under reduced pressure and the reaction mixture partitioned between H2O and EtOAc. The EtOAc layer was washed with sat. NaHCO3, brine, and dried over Na2SO4. The solvent was evaporated under reduced pressure and the crude residue purified by flash chromatography eluting with petroleum ether/EtOAc (4/1) to give 3,4-dihydroquinoxalin-2(1H)-one (560 mg, 38%) as yellow solid. LC-MS (ES-API); rt 7.40 min; m/z calculated for C8H8N2O [M+H]+ 149.0, found 149.0.

Provenance & Evidence