Synthesis and antimicrobial activity of substituted tetrahydroindazoles and cyclohexanones

Abstract

2,4-Dibenzyloxy(diallyloxy)carbonylcyclohexanones (I -XIV) were reacted with hydrazine hydrate via the 1,3-dioxo fragment to form tetrahydroindazoles (XV -XXVIII). Interaction of b-cycloketols (I -XIV) with phenylhydrazine in all cases led to the formation of phenylhydrazones (XXIX -XXXVI). The structures of compounds XV -XXVI were confirmed by IR and 1 H NMR spectroscopy. Results obtained from studies of the antimicrobial activity of the compounds synthesized are presented.The nature of the alkyl radical in the alkoxycarbonyl group of b-cycloketols is known to affect the rate and direction of reactions with nucleophilic reagents [1 -5]. Thus, dimethoxy-[4], diethoxy-[1 -3], and diisopropoxycarbonyl-substituted cyclohexanones [5] interact with hydrazine hydrate to form tetrahydroindazoles, and di-tert-butoxycarbonyl-substituted cycloketols form hydrazones [4].In reactions with phenylhydrazine, independently of the nature of the allyl radical in the alkoxycarbonyl group, derivatives form at the carbonyl group of the alicycle, forming phenylhydrazones [1, 5], though diacetyl-substituted cycloketols are known [1] to interact with phenylhydrazine via the 1,3-dioxo fragment and heterocyclization to form the corresponding indazoles. The absence of cyclization in the case of alkoxycarbonyl substituents appears to be associated with the low electrophilicity of the carbon atom of the ester substituent as compared with the acetyl substituent. Antimicrobial activity has been observed in a series of substituted b-cycloketols and their derivatives [6].The aims of the present work were to conduct further studies of the effects of the alkyl radical in the alkoxycarbonyl group on the direction of reactions with nucleophilic reagents, to obtain new condensed heterocyclic systems, and to study their antimicrobial actions; reactions with hydrazine and phenylhydrazine were used to introduce previously described substrates [6] -2,4-dibenzyloxy(diallyloxy)carbonylcyclohexanones (I -XIV).Unlike the substituents already studied [1 -5], alkyl and benzyl radicals have electron-acceptor properties, which produces some increase in the positive charge on the carbon 319 0091-150X/07/4106-0319

Synthesis and Spectral Studies of R(2),C(4)-Bis(Tert-Butoxycarbonyl)-C(5)-Hydroxy-T(5)-Methyl-T(3)-Phenyl Cyclohexanone and Their Biological Activity

“…Heterocyclic compounds are an important class and have been found as a crucial structural core in natural and synthetic drugs [12]. In recent years, β-keto esters have displayed a number of important biological properties such as bactericidal, fungicidal, and anti-inflammatory activities [13][14][15]. Antioxidants have gained a lot of importance because of their potential prophylactic and therapeutic activities against many diseases.…”

Synthesis and Antimicrobial Activity of Novel Hydrazone and 1,2,4-Triazole-3-thione Derivatives

“…The synthesis and determination of the practical value of hydrazones are relevant, since a hydrazone fragment is present in the molecules of a number of biologically active compounds [1], which have antimicrobial [2][3][4][5], anti-inflammatory [6], analgesic [7], antiprotozoal [8], antituberculous [9], anticonvulsant [10], and cardioprotective activity [11]. The combination of different functional groups in hydrazones results in a large number of compounds with unique physical and chemical properties.…”