Benzonitrile, 4-chloro-3-nitro- → 7-cyano-3,4-dihydroquinoxalin-2(1H)-one

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Reaction Steps

To a solution of 4-chloro-3-nitrobenzonitrile (18.3 g, 100 mmol) and glycine methyl ester-hydrochloride (12.3 g, 100 mmol) in EtOH (150 mL) was added NaHCO3 (25.2 g, 300 mmol), and the resulting mixture was refluxed for 16 hours. The mixture was filtered and the filtrate was concentrated. The resulting residue was partitioned in EtOAc and water. The organic layer was neutralized with 1N HCl to pH 7 and then washed with brine, dried over MgSO4, and concentrated to give a crude (25 g). A solution of the crude was hydrogenated in MeOH (500 mL) in the presence of 10% Pd on carbon (1.5 g) at room temperature for 6 hours. The mixture was filtered and the filtrate was concentrated to give more of the same product (19.5 g, 100%). 1H NMR (DMSO-d6) δ 10.50 (s, 1H), 7.15 (dd, J=8.1 Hz, J=1.8 Hz, 1H), 6.94 (d, J=1.6 Hz, 1H), 6.93 (s, 1H), 6.68 (d, J=8.4 Hz, 1H), 3.90 (d, J=1.1 Hz, 2H); MS(CI) m/z 191 (M+NH4).

Provenance & Evidence