Glycine-Catalyzed Efficient Synthesis of Pyranopyrazoles via One-Pot Multicomponent Reaction

One-pot, four-component synthesis of pyrano[2,3-c]pyrazoles catalyzed by sodium benzoate in aqueous medium

“…13 Afterwards several other synthetic approaches to synthesis of these compounds were reported. These approaches include one-pot three-component condensation of pyrazolone derivatives, malononitrile, and aromatic aldehydes or pyrazole-aldehydes; 14 three-component cyclocondensation of substituted piperidin-4-ones, pyrazol-5-ones, and malononitrile; 15 four-component reaction of aldehydes, ethyl acetoacetate, malononitrile with hydrazine hydrate; [16][17][18][20][21][22][23][24][25][26][27][28][29][30][31][32] two-component reaction of 3-methyl-2-pyrazolin-5-one with benzylidenemalononitriles; 19 and four-component reaction involving aromatic aldehydes, Meldrum's acid, hydrazine hydrate, and ethyl acetoacetate. 32 Various catalysts and conditions have been used to synthesis pyranopyrazoles, via reactions mentioned above.Some of those catalyst are triethylamie in ethanol or water, 14a,15 p-dodecylbenesulfonic acid (DBSA) in water at 60 °C, 14c hexadecyltrimethylammonium bromide (HTMAB) at 60-80 °C, 14d ammonium acetate in ethanol, 14g triethylbenzylammonium chloride (TEBACl) at 90 °C in water solution, 14i β-cyclodextrin in water, 16 imidazole in aqueous medium, 17 piperidine in ethanol or water, 14h,18 cinchona alkaloid organocatalysts in dichloromethane, 19 per-6-amino-β-cyclodextrin (per-6-ABCD) , 20 Brønsted-acidic ionic liquid under solvent-free conditions, 21 [bmim]OH, 22 L-proline and γ-alumina, 23 32 and cetyltrimethylammonium chloride (CTACl).…”

ZnFe2O4 Nanoparticles as a Robust and Reusable Magnetically Catalyst in the four Component Synthesis of [(5-hydroxy-3-methyl-1H-pyrazol-4yl) (phenyl) Methyl]propAnedinitriles and Substituted 6-Amino-Pyrano[2,3-c]Pyrazoles

“…[4][5][6] Substituted 6-aminopyrano [2,3-c]pyrazoles were first synthesised by a reaction between 3-methyl-5-pyrazolone with tetracyanoethylene. 7 Various 2,4-dihydropyrano [2,3-c] pyrazole-5-carbonitriles were synthesised using γ-alumina, 8 piperidine, 9 imidazole, 10 glycine, 11 [(CH 2 ) 4 4 ], 12 as a catalyst. Although many methods for the synthesis of pyrano [2,3-c]pyrazoles are known, some have drawbacks, including long reaction times, difficult purification, high catalyst loading and non-reusable catalyst, and may require special conditions.…”

Ag/Tio2 Nano Thin Films Catalyzed Efficient Synthesis of 6-Amino-4-Aryl-3-Methyl-1,4-Dihydropyrano[2,3-C] Pyrazole-5-Carbonitriles At Green Conditions

“…Moreover, dihydropyrano [2,3-c]pyrazoles exhibit molluscicidal activity 29 , and has been identified as a screening kit for Chk1 kinase inhibitor 30 . Because of the importance of these compounds, a number of methods have been reported for their synthesis in the presence of various catalysts such as ionic liquids 31,32 , organic bases [33][34][35][36] , amberlyst 37 , glycine 38 , per-6-amino-b-cyclodextrin 39 , and iodine 40 .…”