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

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.

1. waitat 80° C. for 3 h
2. customThe DMF was evaporated under reduced pressure
3. customthe reaction mixture partitioned between H2O and EtOAc
4. washThe EtOAc layer was washed with sat. NaHCO3, brine
5. dry with materialdried over Na2SO4
6. customThe solvent was evaporated under reduced pressure
7. customthe crude residue purified by flash chromatography
8. washeluting with petroleum ether/EtOAc (4/1)

ORD record

ord-41db82ad277b476eaf9f89c964a0c614

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09062076B2