N-bromobutanimide → ethyl 4-ethoxy-1-vinyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate
Reaktionsgleichung
[CH2:1]([N:3]1[C:7]2=[N:8][CH:9]=[C:10]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[C:11]([O:12][CH2:13][CH3:14])=[C:6]2[CH:5]=[N:4]1)[CH3:2].BrN1C(=O)CCC1=O>C(Cl)(Cl)(Cl)Cl>[CH2:13]([O:12][C:11]1[C:10]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:9][N:8]=[C:7]2[N:3]([CH:1]=[CH2:2])[N:4]=[CH:5][C:6]=12)[CH3:14]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A suspension of ethyl 1-ethyl-4-ethoxy-1H-pyrazolo[3,4-b]pyridine-5-carboxylate (which may be prepared as described in U.S. Pat. No. 3,755,340, for example, Example 1c) (14.24 g.) and N-bromosuccinimide (21.2 g.) in carbon tetrachloride (109 ml.) was stirred and heated under reflux while being irradiated with a sun lamp (Westinghouse 250 watt). After 1.5 hours the mixture was cooled (ice-bath) and filtered. The filtrate was washed with aqueous sodium bicarbonate and water, dried (MgSO4) and evaporated to give ethyl 4-ethoxy-1-vinyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylate as a yellow oil.