Synthesis and antimicrobial activity of pyrazolinones and pyrazoles having benzothiazole moiety

Abstract

A new class of 4-arylhydrazono-1-benzothiazolyl-3-methylpyrazolin-5-ones (3a-j) and 4-arylazo-1-benzothiazolyl-3,5-dimethylpyrazoles (4a-j) were designed as pharmacophore hybrids between pyrazolinone/pyrazole and benzothiazole moiety. The target molecules were efficiently synthesized by the cyclization of various oxobutyrates/pentane-2,4-dione derivatives with 6-chloro-2-hydrazinobenzothiazole in the presence of glacial acetic acid. The compounds were evaluated for their in vitro antimicrobial activity. Preliminary study of the structureactivity relationship revealed that electron-withdrawing groups in phenyl ring had a promising effect on the antimicrobial activity. Also, correlation study has been used to establish the relationships between the antibacterial activity and physicochemical parameter clogP.

A comprehensive review in current developments of benzothiazole-based molecules in medicinal chemistry

“…In BTA-pyrazoles conjugates, compound (29a) (MIC 15.58 mM against S. aureus) and (29b) (MIC 32.46 mM against E. coli) having p-chloro and p-fluoro group in the phenyl ring, respectively, displayed significant antibacterial activity. From SAR, the incorporation of 6-chloro BTA pharmacophore in the pyrazolinone/pyrazole derivatives enhanced the antimicrobial activity, and compounds having electron-withdrawing groups are more active than compounds having electron-donating groups at the phenyl ring attached by hydrazino/azo linkage at the position 4-of pyrazolinone/pyrazole moieties [74]. Bolelli and co-workers synthesized a series of BTA derivatives and evaluated for antimicrobial activities with different strains.…”

Synthesis of Benzothiazoles via Condensation Reaction of 2‐Aminothiophenols and β‐Oxodithioesters Using a Combination of PTSA and CuI as Catalyst

“…Due to immense importance of benzothiazole derivatives, it has been attracted attention to the synthetic organic chemist. These molecules exhibit a broad range of pharmacological activities such as anti‐microbial, anti‐convulsant, anti‐tubercular, anti‐viral and anti‐inflammatory . In addition, benzothiazole derivatives found several interesting applications in chemo‐sensing, cosmetics, dyes and rubber industries.…”

Synthesis, Molecular Docking and Antimicrobial Evaluation of Some Benzothiazoles

“…Benzothiazoles are important class of heterocyclic compounds possessing signi cant biological activities and interesting chemical features. Various benzothiazole derivatives are reported to possess broad spectrum of biological activities such as antimicrobial [1][2][3][4][5][6], antitubercular [7][8], anticancer [9][10], anticonvulsant [11][12], antidiabetic [13][14], antiviral [15] and anti-in ammatory [16]. Benzothiazole also showed antimicrobial activity through inhibition of DNA gyrase [17][18].…”