Title:Polyethylene Glycol-400 Prompted an Efficient Synthesis of Thienyl Pyrazolo[
1,5‐a] Pyrimidines as Microbial Inhibitors
Volume: 19
Issue: 6
Author(s): Shankaraiah G. Konda*, Santosh S. Chobe, Amit Kumar N. Gosar, Baliram S. Hote, and Gajanan G. Mandawad*
Affiliation:
- Department of Chemistry, K.J. Somaiya College, Kopargaon-423601, Maharashtra, India
- Department of Chemistry,
Maharashtra Udayagiri College, Udgir-413517, Maharashtra, India
- Department of Chemistry,
Maharashtra Udayagiri College, Udgir-413517, Maharashtra, India
Keywords:
Green synthesis, polyethylene glycol-400, chalcones, 5-amino pyrazole, pyrazolo [1, 5-a]pyrimidines, antimicrobial activity.
Abstract:
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
α, β‐ 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.