Polyethylene Glycol-400 Prompted an Efficient Synthesis of Thienyl Pyrazolo [1,5-a] Pyrimidines as Microbial Inhibitors

Aims: The aim of this present work was to design and establish an efficient synthesis of new thienyl pyrazolo [1,5-a] pyrimidines using an environmentally friendly reaction solvent. Further, the newly synthesized compounds were evaluated for antimicrobial activity. Materials and Methods: A series of thienyl pyrazolo [1,5-a] pyrimidines have been synthesized by the condensation reaction of 4-(4'-chloro-phenylazo)-5-amino pyrazole with alpha, beta- unsaturated carbonyl composites (chalcones) using NaOH in polyethylene glycol-400 as a green reaction solvent. The dissemination technique recommended by the National Clinical Laboratory Standards Committee was used to study the antimicrobial activities of synthesized compounds. Results and Discussion: Polyethylene glycol-400 prompting an efficient synthesis of thienyl pyrazolo [1,5-a] pyrimidines have been discussed. Excellent yields of the products were obtained in a shorter reaction time using PEG 400 as a green reaction solvent. The reaction solvent was recovered and reused without the loss of its activity. The synthesized compounds have shown interesting antibacterial activity. Hydroxyl and halo substitution with thienyl moiety emerged as an active antibacterial and antifungal study. Conclusion: The advantage of this methodology is that it incorporates the green method, has excellent yields, easy workup, avoids toxic solvents, and an expensive catalyst. The new dimension pyrazolo [1,5-a] pyrimidine derivatives with thienyl moiety exhibit promising anti-microbial activity.