Modified Neoflavones Based on 7-Hydroxyneoflavone-6-Enamino Ketone and 7-Hydroxy-3-Hetarylbenzopyran-2- and 4-Ones Mannich Bases and Their Recyclization

The interaction of 7-hydroxyneoflavone-6-enamino ketone with 8-dialkylamino-7-hydroxy-3-hetarylbenzopyran-2- and 4-ones led to the formation of 10-methyl-4-phenyl-2H,6H-pyrano[3,2-g]-chromen-2,6-dione, which incorporated coumarin or chromone fragments at C-7 using a methylene linker. The recyclization of 7-[3-(1,3-benzothiazol-2-yl)-7-hydroxy-2-oxo-2H-8-chromenylmethyl]-10-methyl-4-phenyl-2H,6H-pyrano[3,2-g]chromene-2,6-dione and 7-[6-ethyl-7-hydroxy-3-(4-methyl-1,3-thiazol-2-yl)-4-oxo-4H-8-chromenylmethyl]-10-methyl-4-phenyl-2H,6H-pyrano[3,2-g]chromene-2,6-dione was investigated under the influence of N,N- and N,O-binucleophiles.