Synthesis, Characterization and anti -HIV Activity of 4-hydroxy-3-(5-methyl-1- phenyl-1H-pyrazol-3-yl)pyrano(3,2-c)chromene-2,5-dione

8797 A B ST R A C T Substituted 4-hydroxy -2H,5H pyrano (3,2-C) chromene - 2,5 - dione (I) have been prepared by 4-Hydroxy coumarin when treated with phosphorus oxychloride and zinc chloride. (I) on reaction with acetic acid and phosphorous oxychloride to give 3- acetyl 4- hydroxy -2H,5H pyrano (3,2-C) chromene - 2,5 - dione (II). Which on heating with ethyl acetate and pulverized sodium metal for several hours afforded 4-hydroxy-3-(3- oxobutanoyl)2H,5H pyrano(3,2-c)chromene-2,5-dione (III) . (III) when treated with ethanol and phenyl hydrazine afforded to give 4-hydroxy-3-(5-methyl-1-phenyl-1H-pyrazol-3- yl)pyrano(3,2-c)chromene-2,5-dione (IV). Several of similar derivatives were also synthesized. The structures of the synthesised compounds have been assigned on the basis of elemental analyses, IR, NMR and mass spectral studies.