Unraveling the Potential Role of Deep Eutectic Solvents (DESs): Synthesis of Ketazines & Pyrazolines

Abstract

AbstractIncreasing demand to curtail the usage of hazardous organic solvents, reagents and/or catalysts, has engrossed the interest of the scientific community towards the development of next generation liquid media, commonly known as the ‘deep eutectic solvents’ (DESs). Bearing the significant role of ketazine and pyrazoline derivatives in mind, herein, after screening various DESs for the condensation of ketones and hydrazine followed by the cyclization to produce corresponding pyrazolines, a low melting mixture of citric acid: N,N‐dimethyl urea (CA:DMU) in 2 : 3 ratio was found to be the best choice for this particular transformation. Interestingly, the DESs was recycled easily and reused up to four times without affecting the yield of the product to a greater extent. Hopefully, this method may be useful to generate different kinds of valuable ketazines as well as pyrazoline derivatives of particular interest in years to come.