Novel pyrazolopyrones from enol lactones

Abstract

1609-1613The one pot and facile condensation reaction of 5-chloro-3-methyl-1-phenylpyrazole-4-carboxaldehyde 1, 5-azido-3-methyl-1-phenylpyrazole-4-carboxaldehyde 2 with triacetic acid lactone 3 and 4-hydroxycoumarin 4 affords isomeric pyrazolopyrones viz. 4-(4-hydroxy-6-methyl-2-oxo-2H-pyran-2-one-3-yl)-3,7-dime­th­yl-1-phenylpyrazolo­[3,4:2,3]-4H-pyrano [3,2-b]pyran-5-one 6, 4-(4-hydroxy-6-methyl-2-oxo-2H-pyran-2-one-3-yl)-3,7-dimethyl -1-phenylpyrazolo[3,4:2,3]-4H-pyrano[3,2-c]pyran-5-one 7 and 4-(4-hydroxy-2-oxo-2H-1-benzopyran-2-one-3-yl)-3-methyl-1-phenyl­pyrazolo[3,4:2,3]-4H-pyrano[3,2-b]-1-benzopyran-5-one 8, 4-(4-hydroxy-2-oxo-2H-1-benzopyran-2-one-3-yl)-3-methyl-1-phenyl­pyrazolo[3,4:2,3]-4H-pyrano[3,2-c]-1-benzopyran-5-one 9 res­pecti­­vely. The condensation reaction which has led to the forma­tion of isomeric compounds is similar to Simonis conden­sa­tion reaction of oxoesters. The structures of all newly synthesized compounds have been determined by IR, 1H NMR and mass spectral data