| Abstract: | ![]()
Reaction of 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans, 4-hydroxycoumarin and formaldehyde gave rise to the formation of 1-oxo-2-((2-oxo-4′-hydroxy-2′H-1′-benzopyran-3′-yl)-melhyl J-3-dialkylamino-1H-naphtho[2,1-b]pyrans. When these compounds were refluxed in glacial acetic acid, cyclization occurred and 6,8-dioxo-6H,7H,07-,5,15,16-trioxadibenzo[a,j]-naphthacene arose by cleavage of the dialkylamino group. In a similar manner, starting from suitable products, many other trioxanaphthacene or azadioxanaphthacene derivatives were synthesized. |
