Synthetic strategies for 1,4,5/4,5-substituted azoles: A perspective review

Azole nucleus represents an important class of biologically active compounds that are gaining more attention in the field of medicinal chemistry due to large number of structure diversity. Among azoles, pyrazoles, and isoxazoles five-membered nitrogen containing heterocyclic compounds are associated wide range of biological activities such as anticancer, antimicrobial, anti-inflammatory, antioxidant, etc. Some of azole derivatives (e.g., 1,4,5-trisubstituted pyrazoles, 4,5-disubstituted isoxazoles, and 4,5-disubstituted-1H-pyrazoles) are still unexplored in literature, these unexplored azoles have fascinated the consideration of many researchers to study their framework synthetically and biologically. This present review is an attempt to update and understand the chemistry of unexplored pyrazoles and isoxazoles along with their medicinal importance. This article would definitely help the researchers to bring further enhancement in the synthesis of biologically active pyrazoles and isoxazoles.