Studies on Synthesis and Characterization of Nitrogen Heterocycles as Metal Chelates and Their Biological Investigations

Abstract

This chapter deals with new convenient approach for the preparation of substituted pyrazoles derivatives. The present method delivers the use of a recyclable PEG-400 as a green reaction solvent. The described synthetic pathway offers an easy access for the preparation of 4-((4-substituted phenyl) diazinyl)-1H-pyrazole-3,5-diamine and 3,5-diamino-4-((4-substitutedphenyl)diazinyl)-1H-pyrazole-1-carbothioamide/carboxamide derivatives over green chemistry protocol. The newly synthesized pyrazolederivatives were characterized by using spectroscopic techniques. newlineChapter 2 newlineOver the years pyrazole containing heterocycles form a fundamental position in medicinal chemistry and are well known for showing variety of pharmacological activities such as anticancer, antitubercular, antiviral, antiinflammatory, antimicrobial and antidiabetic. Due to importance of pyrazole derivatives, we have reported the compounds 4-((4-substituted phenyl)diazinyl)-1H-pyrazole-3,4-diamine and 3,5-diamino-4-((4- substututedphenyl)diazinyl)-1H-pyrazole-1-carbothioamide/carboxamide derivatives are screened for their anticancer and antitubercular activities. Among the synthesized derivatives, the compounds 1e and 1h were newlineexhibit very good anticancer activities. While other derivatives 1e and 1i showed promising activity against Mycobacterium tuberculosis (Mtb) strain when compared with recently used drugs such as Isoniazid, Ethambutol and Rifampicin. Molecular docking of designed active compounds were carried out, which indicating the potential hydrogen bonding against Mycobacterium tuberculosis. newlineChapter3 newlineThis chapter deals with the multi-component tactic by knowing the importance of multi-component reactions. Here we have synthesized fused pyrazole derivatives via one pot multicomponent approach. As per concern to environmental benign PEG-400 played important role of green solvent for the synthesis of 4-methyl-3-(4-substituted phenyl) pyrazolo[3,4-c] pyrazole-2- (6H)- carboxamide pyrazole derivatives (2d-f). The synthesized derivatives were characte