Synthesis and Characterization of New 3,5-Dinaphthyl Substituted 2-Pyrazolines and Study of Their Antimicrobial Activity

Abstract

A number of chalcones were prepared by condensing either 1-acetylnaphthalene or substituted 1-acetylnaphthalenes with 1-naphthaldehyde or 4-dimethylamino-1-naphthaldehyde in ethanolic NaOH solutions. These chalcones were immediately reacted with hydrazine hydrochloride, phenyl hydrazine and semicarbazide hydrochloride in the presence of dry acetic acid to obtain the corresponding 2-pyrazolines. The synthesised heterocycles were characterized on the basis of their chemical properties and spectroscopic data. These compounds were tested for antimicrobial activity against a variety of test organisms: Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabillis, Shigella dysentry and Salmonella typhii. The compounds containing chloro, hydroxo and dimethylamino -N(CH3)2 group as substituents on the naphthalene rings have been found to be very effective antimicrobial agents. In addition, the presence of a carboxamido -CONH2 substituent group at the N-1 position of the 2-pyrazoline rings is shown to contribute substantially to the antimicrobial activity.

Mild and efficient oxidation of 2-pyrazolines and isoxazolines by trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxalane–NH4Cl–HOAc in water–MeCN

“…IR spectra were recorded on a Perkin Elmer GX FT IR spectrometer (KBr pellets). 2-Pyrazolines and isoxazolines used in this work were all prepared as reported elsewhere [11,[14][15][16]. 2-Pyrazoles and isoxazoles were characterized by comparison of their melting points and IR, 1 H NMR, and 13 C NMR spectra with reported data.…”

“…Isoxazoles and pyrazoles are also useful synthetic intermediates capable of undergoing a variety of transformations and transition-metal catalyzed cross-coupling reactions, for example Heck, Stille, Suzuki, Sonogashira, and Negishi coupling [9]. Isoxazoles and pyrazoles are also in demand because of their importance both as synthetic intermediates [10] and as pharmacological agents [11]. Isoxazoles and 2-pyrazoles can be easily obtained by oxidation of isoxazolines [12][13][14][15][16][17] and 2-pyrazolines [18], respectively.…”

One-pot diastereoselective synthesis of new spiro indenoquinoxaline derivatives containing cyclopropane ring

“…7 Many synthetic methods have been reported for the preparation of cyclopropanes such as intramolecular cyclization, addition of carbenes to olefins and Michael initiated ring closure (MIRC). 1,8 In this study along our pervious works on the synthesis of spiro indenoquinoxalines and other biologically active compounds, 9,10 we report a novel one-pot facile procedure for the synthesis of some spiro indenoquinoxaline-cyclopropane derivatives which directly prepared from chalcones of indenoquinoxaline.…”

Synthesis, Tautomeric Structure, Dyeing Characteristics, and Antimicrobial Activity of Novel 4-(2-Arylazophenyl)-3-(2-hydroxyphenyl)-1-phenyl-2-pyrazolin-5-ones

“…Much attention has been devoted towards the usage of many azopyrazolone derivatives due to their interesting structural properties and applications in divers area. [1][2][3][4][5][6][7][8][9][10][11][12] On the other hand, they are of particular importance in dye chemistry, 13,14 because many of them were used as good fastness dyestuffs for almost all kind of fabrics, whether natural or synthetic.…”