Dimethylformamide → HCID 13175316, Verbindung

Reaktionsgleichung

CN(C)C=O.Cl[C:7]([O:9][CH2:10][CH3:11])=[O:8].[O:12]=[C:13]1[N:18]2[C:19]3[C:24]([NH:25][CH2:26][C:17]2=[N:16][CH:15]=[C:14]1[C:27]([O:29][CH2:30][CH3:31])=[O:28])=[CH:23][CH:22]=[CH:21][CH:20]=3>O>[O:12]=[C:13]1[N:18]2[C:19]3[C:24]([N:25]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[CH2:26][C:17]2=[N:16][CH:15]=[C:14]1[C:27]([O:29][CH2:30][CH3:31])=[O:28])=[CH:23][CH:22]=[CH:21][CH:20]=3

Komponenten

Versuchsvorschrift

4 ml of dry dimethylformamide were saturated with nitrogen for 10 minutes before 150 mg of ethyl chloroformate and 280 mg of ethyl 5,6-dihydro-1-oxo-1H-pyrimido [1,2-a] quinoxaline-2-carboxylate were added thereto. The solution obtained was left at room temperature overnight and then was poured into water. The mixture was extracted with ethyl acetate and the organic phase was dried over MgSO4 and evaporated to dryness. The residue was chromatographed over silica gel and eluted with ethyl acetate to obtain 140 mg (41% yield) of diethyl 5,6-dihydro-1-oxo-1H-pyrimido [1,2-a] quinoxaline-2,6-dicarboxylate melting at 140°-2° C.