Diethyl (ethoxymethylene)malonate → Diethyl {[(4-oxo-4H-1-benzopyran-3-yl)amino]methylene}propanedioate
Reaction equation
[NH2:1][C:2]1[C:11](=[O:12])[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[O:4][CH:3]=1.C(O[CH:16]=[C:17]([C:23]([O:25][CH2:26][CH3:27])=[O:24])[C:18]([O:20][CH2:21][CH3:22])=[O:19])C>>[O:12]=[C:11]1[C:10]2[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=2[O:4][CH:3]=[C:2]1[NH:1][CH:16]=[C:17]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[C:23]([O:25][CH2:26][CH3:27])=[O:24]Participants
3
Conditions
- Temperature
- 140 °C
Procedure
A mixture of 3-aminochromone (8.0 g, 0.05 mole) and diethyl ethoxymethylenemalonate (17.3 g, 0.08 mole) was heated under nitrogen at 140° C. for 2.5 hrs. The reaction mixture was cooled. The product, which crystallized out was filtered off and triturated with petroleum ether. Recrystallization from ethyl acetate - absolute ethanol gave white crystals (10.3 g, 62.5%), m.p. 155°-157° C.