Dimethylformamide → 2,3-Dihydro-1H-3a,6-diaza-cyclopenta[a]indene-8-carbaldehyde
Reaktionsgleichung
P(Cl)(Cl)(Cl)=O.[CH2:6]1[C:10]2=[CH:11][C:12]3[CH:13]=[N:14][CH:15]=[CH:16][C:17]=3[N:9]2[CH2:8][CH2:7]1.CN(C)[CH:20]=[O:21]>>[CH2:6]1[C:10]2=[C:11]([CH:20]=[O:21])[C:12]3[CH:13]=[N:14][CH:15]=[CH:16][C:17]=3[N:9]2[CH2:8][CH2:7]1Komponenten
4
Versuchsvorschrift
To dimethylformamide (0.3 ml) was added phosphorus oxychloride (0.33 ml) dropwise at 0° C. The mixture was allowed to stir for 10 min at room temperature. A solution of 2,3-dihydro-1H-3a,6-diaza-cyclopenta[a]indene (0.10 g 0.63 mMol) in 0.1 ml dimethylformamide was added and the mixture was stirred at room temperature for 3 h. The reaction was quenched with ice (ca 5 g) and the pH was adjusted to 9 by addition of 28% sodium hydroxide. The mixture was heated to reflux for 10 min. cooled to room temperature and extracted with ethyl acetate(3×5 ml) The combined organic extracts were dried with sodium sulfate and evaporated to dryness to yield the title compound (0.115 g, 97% Th). For analytical purposes a sample was recrystallised from ethyl acetate to afford slightly yellow crystals. mp 150-151° C. Found C, 70.94; H, 5.56; N, 14.97%; C11H10N2O requires C, 70.95; H, 5.41; N. 15.04%