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In search of new generation of triazole based antifungal agents, synthesis of series of new 1,2,3-triazolyl pyrano[2,3-c]pyrazoles under ultrasonic irradiation using NaHCO3 has been reported. The bioevaluation results indicate that, the compounds 7c, 7d, 7e, 7f, and 7i displayed excellent antifungal activity with lower MIC ≤ 25 µg/mL. Most of the compounds from the series showed potent antioxidant activity with a lower IC50 value in the range 09.39 ± 0.42–14.97 ± 0.24 µg/mL, in comparison to butylated hydroxyl toluene (BHT). Molecular docking studies against potential target sterol 14α-demethylase (CYP51) was also performed and showed excellent binding affinity with the target enzyme. Moreover, in silico ADME study shows that the derivatives could serve as drug like molecules for further drug development in clinical research. [ABSTRACT FROM AUTHOR]

Synthesis of pyrimido[1,2-a]benzimidazole and pyrano[2,3-c]pyrazole derivatives were achieved using polyethylene glycol (PEG-400) as promoting reaction medium in water under catalyst-free conditions at reflux and room temperature, respectively. The structure of pyrimido[1,2-a]benzimidazole was confirmed using1H NMR,13C NMR, DEPT, and HMBC experiments. The promising points for the present methodology are efficiency, generality, high yield, short reaction time, cleaner reaction profile, ease of product isolation, simplicity, potential of recycling reaction medium, and finally agreement with green chemistry protocols. [ABSTRACT FROM PUBLISHER]

An efficient, high-yielding, and rapid protocol has been developed for the synthesis of diversity-oriented 6-amino-2,4-dihydropyrano[2,3-c]pyrazol-5-carbonitriles derivatives via a four-component, one-pot cyclocondensation reaction of ethyl acetoacetate, hydrazine hydrate, aldehydes, and malononitrile using silica-supported tetramethylguanidine as a heterogeneous catalyst for the first time. The protocol proves to be efficient and environmentally benign in terms of very easy workup, good yields, and ease of recovery of catalyst. In addition, the present method is superior in terms of green media, the amount of catalyst, and reaction time. [ABSTRACT FROM PUBLISHER]

This review highlights the methods used for the synthesis of enaminonitriles of pyrano[2,3-c]pyrazole compounds. Their reactivity and synthetic importance were investigated. In this context, recent progress in the synthesis and use of enaminonitriles of pyrano[2,3-c]pyrazole as precursors for heterocyclic compounds is reviewed. The synthetic routes for preparation of enaminonitriles are based on multicomponent reactions including three- or four-component reactions. Enaminonitriles can be used as building blocks for carbocyclic five-, six-, and seven-membered heterocycles as well as fused heterocyclic compounds. The bibliography includes 94 references. [ABSTRACT FROM AUTHOR]

A series of substituted pyrano[2,3-c]pyrazole derivatives were synthesized by a one-pot reaction of methyl 4-methyl-3-oxovalerate, phenylhydrazine, aromatic aldehyde, and malononitrile in ethanol with catalysis by triethylamine. The title compounds were obtained in good to excellent yields. A possible mechanism for this reaction was proposed. [ABSTRACT FROM PUBLISHER]

A simple and clean method tor producing 6-amino-4-aryl-5-cyano-3-methyl-1-pheny1-1,4-dihydropyrano[2,3-c]pyrazole from aromatic aldehyde, malono-nitrile and 3-methyl-1-phenyl-2-pyrazolin-5 one catalyzed by hexadecyltrimethylammonium bromide (HTMAB) in water is described. This method provides several advantages such as mild reaction conditions, simple workup procedure, and being environmentally friendly. [ABSTRACT FROM AUTHOR]

The diazolones 1a–c were reacted with triethylorthoformate and hippuric acid derivatives 3 to afford the novel pyrano[2,3-c]pyrazole derivatives 4. The latter undergoes ring cleavage by reaction with acetic acid-ammonium acetate and was transformed into the corresponding pyrazolo[3,4-b]pyridine derivatives 6. The reaction of 2-cyanomethyl-benzimidazole 7 with triethylorthoformate and hippuric acid derivatives 3 to give the pyrido[1,2-a]-benzimidazoles 10 has also been discussed. [ABSTRACT FROM AUTHOR]