Recent advances in the synthesis of bis(pyrazolyl)methanes and their applications

Pyrazole and its derivatives are an important class of heterocyclic compounds, present in several biologically and medicinally active compounds. Compounds containing 2,4-dihydro-3H-pyrazol-3-one structural motif, including 4,4 '-(arylmethylene)-bis-(1H-pyrazol-5-ols), have attracted interest because they exhibit a wide range of biological activities and as the chelating and extracting reagents for different metal ions. There are two main strategies to the synthesis of bis(pyrazolyl)methane derivatives. The first involves the one-pot pseudo three-component reactions of 3-methyl-5-pyrazolone derivatives and aldehydes, and the second approach is the one-pot pseudo five-component reactions of beta-keto esters, hydrazins and aldehydes. This review includes the recent investigation in the multi-component synthesis and their applications of bis(pyrazolyl)methanes and describes the literature reports for the period of 2014 to early 2021. Graphic abstract

Automated summary

Pyrazole and its derivatives are important heterocyclic compounds found in biologically and medicinally active compounds. Two main strategies for the synthesis of bis(pyrazolyl)methane derivatives include one-pot pseudo three-component reactions and one-pot pseudo five-component reactions. This review provides an overview of the recent research on the multi-component synthesis and applications of bis(pyrazolyl)methanes from 2014 to early 2021.