Synthesis, Antibacterial and Antifungal Activity of Some New Pyrazoline and Pyrazole Derivatives

Abstract

A series of 2-pyrazolines 5-9 have been synthesized from α,β-unsaturated ketones 2-4. New 2-pyrazoline derivatives 13-15 bearing benzenesulfonamide moieties were then synthesized by condensing the appropriate chalcones 2-4 with 4-hydrazinyl benzenesulfonamide hydrochloride. Ethyl [1,2,4] Condensation of 6,6-dimethyl-4-oxo-4,5,6,7-tetrahydro-1H-indole-2-carbaldehyde (1') with compound 24 or 25 afforded the corresponding Schiff's bases 36 and 37, respectively. Reaction of the Schiff's base 37 with benzoyl hydrazine or acetic anhydride afforded benzohydrazide derivative 39 and the cyclized compound 40, respectively. Furthermore, the pyrazole derivatives 42-44 were synthesized by cyclization of hydrazine derivative 25 with the prepared chalcones 2-4. All the newly synthesized compounds have been characterized on the basis of IR and 1 H-NMR spectral data as well as physical data.Antimicrobial activity against the organisms E. coli ATCC8739 and P. aeruginosa ATCC 9027 as examples of Gram-negative bacteria, S. aureus ATCC 6583P as an example of Gram-positive bacteria and C. albicans ATCC 2091 as an example of a yeast-like fungus have been studied using the Nutrient Agar (NA) and Sabouraud Dextrose Agar (SDA) diffusion methods. The best performance was found for the compounds 16, 17, 19 and 20.

Use of 2-(1-(4-Bromophenyl) Ethylidene)hydrazinecarbothioamide and 2-(5-Chloro-2-Oxoindolin-3-Ylidene)hydrazinecarbothioamide in the Syntheses of 2-Thiohydantoin, Pyrimidine Derivatives: Evaluation of Their Antimicrobial Activities.

“…In addition to signals of (CH) aromatic. Mass spectrum of compound 9 showed molecular ion peak at m/z 398 and 400 (M + , 37 Cl) [20][21][22][23][24] [25]. Structure of 7b also confirmed chemically, thus, acetylation with acetic anhydride under reflux gave 3-(3-acetyl-5-oxo-2-thioxoimidazolidin-1-ylimino)-5-chloroindolin-2-one 11.…”

Optimized Synthesis of Novel Pyrazole Based Thiazole Derivatives and their Antimicrobial Evaluation

“…1 H NMR and spectra were recorded on Varian Gemini 400 MHz and 13 C NMR spectra on Varian Mercury-400, 100 MHz in DMSO-d 6 as a solvent and tetramethylsilane (TMS) as an internal standard. Mass spectra were scanned on a Shimadzu LCMS 2010 spectrometer.…”

“…Pyrazoles and its derivatives are well known for their biological and medicinal, applications, such as antimicrobial [1], antitumor [2], antileukemia [3], antidepressant [4], anticonvulsant [5], antifungal [6] and antitubercular [7]. Pyrazole analogoues can selectively inhibit (cyclooxygenase enzyme) COX-2 [8] they are also expressing anti-inflammatory, analgesic, antihypertensive, antipyretic, sedatives, and antidiabetic activities [9,10].…”

Green One-pot Synthesis of Novel Polysubstituted Pyrazole Derivatives as Potential Antimicrobial Agents

“…[3][4][5][6][7][8][9] Numerous studies have also focused on antibacterial and antifungal properties of pyrazole derivatives. [10][11][12] In a research project, inhibitory activities of some heterocyclic Schiff bases derived from thiocarbohydrazide were assessed against various pathogenic bacterial and fungal strains via measurement of their inhibition zone diameters. One of the synthesized 1,2,4-triazines could block the growth of all selected microorganism.…”