Acetic Acid → Y 9000

Reaktionsgleichung

C(O)(=O)C.S(=O)(=O)(O)O.[O:10]=[C:11]1[C:20]2[C:15](=[N:16][CH:17]=[CH:18][CH:19]=2)[O:14][C:13]2[CH:21]=[CH:22][C:23]([C:25]([CH:27](C(OCC)=O)C(OCC)=O)=[O:26])=[CH:24][C:12]1=2>O>[C:25]([C:23]1[CH:22]=[CH:21][C:13]2[O:14][C:15]3=[N:16][CH:17]=[CH:18][CH:19]=[C:20]3[C:11](=[O:10])[C:12]=2[CH:24]=1)(=[O:26])[CH3:27]

Komponenten

Versuchsvorschrift

A mixture of 7.5 ml of glacial acetic acid, 0.9 ml of concentrated sulfuric acid, 4.5 ml of water and 4.6 g of diethyl 2-(5-oxo-5H-[1]benzopyrano[2,3-b]pyridin-7-yl-carbonyl)malonate is stirred under reflux for 2 hours. The reaction mixture is poured into 50 ml of cool water. The crystalline precipitate is filtered off, and suspended in water. The suspension is alkalified with 10% sodium hydroxide under ice cooling, and extracted with chloroform. The extract is washed thoroughly with water, dried, and concentrated. The residue is recrystallized from toluene to give 7 -acetyl-5-oxo-5H-[1]benzopyrano[2,3-b]pyridine melting at 194°-195°C.