Microwave Assisted Improved Method for the Synthesis of Pyrazole Containing 2,4,-Disubstituted Oxazole-5-one and their Antimicrobial Activity

Abstract

Disubstituted oxazol-5-one and pyrazoles are known to exhibit various biological activities. Therefore, in this work, we designed pyrazole containing 2,4-disubstituted oxazol-5-one (3a-g) as a new class of antimicrobial agents. Synthesis of titled compounds was carried out by two different methods. In the first method (conventional Method A), disubstituted oxazol-5-one (3a-g) was prepared by reacting 1-phenyl-3-p-tolyl-1Hpyrazole-4-carbaldehyde (1a-g) with hippuric acid (2) and sodium acetate, in an acetic anhydride for 2.5 -4 h. In the second method (Method B), the above reaction was carried out under microwave assistance. Compared to the conventional method, the microwave-assisted synthesis of 3,4,5-trisubstituted imidazoles demonstrate several advantages, in terms of reaction time and overall yield. All the test compounds were evaluated for in vitro antibacterial and antifungal activities. In general, compounds with electron withdrawing groups showed good antibacterial and antifungal activities. Among the compound tested, compound (3d) showed highest activity.

Synthesis, Characterization, Antibacterial and Antioxidant Studies of Some Heterocyclic Compounds from Triazole‐Linked Chalcone Derivatives

“…As per the antibacterial activities (Table , 3 a‐g ), the best 1,2,3‐triazole‐chalcone ( 3 f ) moiety was further modified at the chalcone section, which involves the conversion of α, β‐ unsaturated carbonyl system into various heterocyclic moieties such as pyrazoles, isoxazoline, pyrimidines, and cyanopyridine etc. The literature survey reveals that chalcones, pyrazoles, isoxazoline, pyrimidines, and cyanopyridine are biological active species which includes various biological activities. In addition, the enzymes of the shikimate pathway represents an excellent target for the design of new antibacterial agents.…”

Design, Synthesis, Molecular Docking, Admet Studies and Biological Evaluation of Pyrazoline Incorporated 1, 2, 3-Triazole Benzene Sulphonamides

“…Pyrazoles are a class of heterocyclic compounds characterized by 5membered aromatic ring structure composed of three carbon atoms and two nitrogen atoms in adjacent positions. Pyrazole derivatives have a long history of applications in agriculture as herbicides and insecticides as well as in the pharmaceutical industry as antipyretic and anti-inflammatory agents [7][8][9][10][11][12]. Pyrazole derivatives have been reported to show a broad spectrum of biological activity including antibacterial [13], antifungal [14], analgesic [15], anti-inflammatory [16][17][18], neuroprotective [19], estrogen receptor binding [20], antineoplastic [21], activities.…”

Phthaloyl Dichloride–DMF Mediated Synthesis of Benzothiazole‐based 4‐Formylpyrazole Derivatives: Studies on Their Antimicrobial and Antioxidant Activities

“…The pyrazoles possessing a formyl group –CHO at the 4‐position are versatile organic synthetic intermediates for the synthesis of many heterocyclic ring systems such as pyrazolylpyrazolines , pyrazoloquinolinones , 4 H ‐pyrazolopyran , pyrazolylbenzoxazole , pyrazolothiadiazepines , pyrazolyloxazolone , pyrazolyloxadiazolines , pyrazolylthiadiazolines , imidazolylpyrazoles , pyrazolopyridines , chromenopyrazolones , and thiopyranothiazolylpyrazoles . These are equally important in the field of medicinal as well as pharmaceutical chemistry because of significant biological activities, such as anti‐inflammatory , antioxidant, antibacterial, and antifungal activities .…”