Synthesis and activity evaluation of 2-(1-naphtho[2,1-b]furan-2-yl-carbonyl)-3,5-disubstituted-2,3-dihydro-1H-pyrazoles

Abstract

Ethyl naphtho[2,1-b]furan-2-carboxylate (2) on reaction with hydrazine hydrate in presence of acid catalyst in ethanol medium affords naphtho[2,1-b]furan-2-carbohydrazide (3). The reaction of substituted acetophenones (4a-c) with aromatic aldehydes (5a-e) produces chalcones (6a-o) via the Claisen condensation. The reaction of naphtho[2,1-b]furan-2-carbohydrazide (3) with chalcones (6a-6o) in presence of acetic acid as catalyst in dioxane produces 1-(naphtho[2,1-b]furan-2-yl-carbonyl)-3,5-disubstituted-2,3-dihydro-1H-pyrazoles (7a-o). The structures of newly synthesized compounds have been established by elemental analysis and spectral studies. The compounds 7a-o have been evaluated for their antimicrobial activity and some selected compounds evaluated for antiinflammatory, analgesic, anthelmintic, diuretic and antipyretic activities.

Synthesis and Biological Evaluation of Furo[3,2-c]pyrazole-5-carbimidates

“…The synthetic route of title compounds [ (1)(2)(3)(4)(5)(6)(7)(8)(9) and (10)(11)(12)(13)(14)(15)(16)(17)(18)] is shown in Scheme-I. Oxidative difunctionalization of pyrano [3,2-c]pyrazole carbonitriles was done with NCS reagent in methanol medium.…”

“…In this reaction with NCS addition of both chlorine and alkoxy groups takes place crosswise the chromene double bond and resulted the products (1)(2)(3)(4)(5)(6)(7)(8)(9). Annexes to this, compounds (10)(11)(12)(13)(14)(15)(16)(17)(18) were synthesized via dehydrohalogenation on compounds (1-9) with piperidine as a base in solvent methanol at room temperature. The reaction mixture turned to a clear brown coloured solution, followed by the precipitation of product after 6 h. The structures of newly synthesized compounds were characterized on the basis of physical and spectral data.…”

“…The reaction mixture turned to a clear brown coloured solution, followed by the precipitation of product after 6 h. The structures of newly synthesized compounds were characterized on the basis of physical and spectral data. The possible mechanism for the synthesis of compounds (10)(11)(12)(13)(14)(15)(16)(17)(18) is shown in Scheme-II. 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 Ciprofloxacin is taken as a standard drug and its MIC is 1.56 µg/mL against all the four strain.…”

“…The high therapeutic properties of the furan related drugs have encouraged the researchers to synthesize a large number of novel pharmacological agents which can act on various receptors in the body as MAO inhibitors [6], kappa opioid receptor agonist [7], sigma receptor agonist, γ-amino butyric acid receptor Synthesis and Biological Evaluation of Furo[3,2-c]pyrazole-5-carbimidates SRAVANTHI SILIVERI 1,2,*, , HARINADHA BABU VAMARAJU 1 and SHIVARAJ 3 agonist, COX-2 inhibitor [8], β-blockers [9], muscarinic receptor agonist, α-adrenergic blockers, calcium channel blockers [10] etc. Furan drugs have broadened scope in remedying various dispositions in clinical medicines [11][12][13][14][15]. Apart from pyrazole and furan, annulated furo pyrazoles are important structural motifs in the domain of medicinal chemistry due to their myriad biological activities.…”

Pyrazole Carbohydrazide Derivatives of Pharmaceutical Interest

“…Antimicrobial activity could be observed for the 1 H -indole-2yl group (compounds 6 – 8 ) with moieties such as 4-methylthiophene-3-yl (compound 5 ) and 1-(naphtho[2,1- b ]furan-2-yl) (compound 10 ) connected to the carbonyl group of the carbohydrazide function [6,11,12]. The derivative 5 also exhibited analgesic activity [11].…”