A series of pyranopyrazoles, namely, 7-(2-aminoethyl)-3,4-dimethyl-1-phenyl-1H-pyrazolo[3,4-b]pyridin-6(7H)-one (2), (Z)-3,4-dimethyl-1-(4-((4-nitrobenzylidene)amino)phenyl)pyrano[2,3-c]pyrazol-6(1H)-one (5), 1-(4-(3,4-dimethyl-6-oxopyrano[2,3-c]pyrazol-1(6H)-yl)phenyl)-3-(naphthalen-1-yl)urea (6), (Z)-ethyl 4-((3,4-dimethyl-6-oxo-1,6-dihydropyrano[2,3-c]pyrazol-5-yl)diazenyl)benzoate (8) and 3...

The crystal structure of the title compound, C(25)H(18)ClN(5)O, was determined in the course of our studies on the synthesis of 1,4-dihydro-pyrano[2,3-c]pyrazole as an inhibitor of the p38 mitogen-activated protein kinase (MAPK). The compound was prepared via a base-catalysed synthesis from 1-benzyl-3-(4-pyrid-yl)-1H-pyrazol-5(4H)-one with p-chloro-aldehyde and malononitrile. The crystal data o...

3,4-ِDihydropyrano[c]chromene derivatives were synthesized using sulfonic acid functionalized silica (SiO2-Pr-SO3H) as a highly efficient heterogenous solid acid catalyst via one-pot three-component condensation of aromatic aldehydes with malononitrile and 4-hydroxycoumarin in excellent yields.

Highly substituted 1,4-dihydropyrano[2,3-c]pyrazole derivatives were synthesized by four-component reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and various phenylhydrazine, using nickel ferrite as a recyclable nanocatalyst by a grinding method under solvent-free and thermal conditions. The reaction has the advantages of good yields, less pollution, ease of separation of the...

Arylidene-Δ2-pyrrolin-4-ones undergo organocatalyzed annulation with malononitrile, furnishing dihydropyrano[3,2-b]pyrroles (18 examples, 0–77% ee in dichloromethane, 11–44% methanol). The products could be enantiomerically enriched by trituration (11 95–99% ee). Enantioselectivity was dependent on the nature of substrate and conformation catalyst, which turn solvent-controlled. reaction mechan...