N,N-Dimethylaniline → Methyl 3-chloro-2-(4-fluorophenyl)quinoxaline-6-carboxylate
Reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[C:17](=O)[NH:16][C:15]3[C:10](=[CH:11][CH:12]=[C:13]([C:19]([O:21][CH3:22])=[O:20])[CH:14]=3)[NH:9]2)=[CH:4][CH:3]=1.O=P(Cl)(Cl)[Cl:25].CN(C)C1C=CC=CC=1>>[Cl:25][C:17]1[C:8]([C:5]2[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=2)=[N:9][C:10]2[C:15]([N:16]=1)=[CH:14][C:13]([C:19]([O:21][CH3:22])=[O:20])=[CH:12][CH:11]=2Participants
4
Conditions
- Temperature
- 110 °C
Procedure
Into a 100-mL round-bottom flask, was placed methyl 2-(4-fluorophenyl)-3-oxo-1,2,3,4-tetrahydroquinoxaline-6-carboxylate (1.2 g, 4.00 mmol, 1.00 equiv), POCl3 (12.2 g, 80.26 mmol, 20.00 equiv), N,N-dimethylbenzenamine (4.9 g, 40.50 mmol, 10.00 equiv). The resulting solution was stirred for overnight at 110° C. in an oil bath. The resulting mixture was concentrated under vacuum and diluted with 50 mL of water. The pH value of the aqueous solution was adjusted to 7 with sodium bicarbonate (4 mol/L). The resulting mixture was concentrated under vacuum and purified by silica gel chromatography with ethyl acetate/petroleum ether (1:40). This resulted in 0.5 g (40%) of methyl 3-chloro-2-(4-fluorophenyl)quinoxaline-6-carboxylate as a white solid.