Green synthesis of Schiff bases: a review study

Abstract

Objectives: Green chemistry is the field that implies instruments and procedures, by which it offers significant environmental and financial benefits above traditional synthetic methods. The modern attention in green chemistry has pretended an additional need for organic synthesis in which different reaction environments must locate, which decreases the use of toxic organic solvents or toxic chemicals.These green methods must enhance the selectivity, shorten reaction time, and make the products isolation simpler than the ordinary routes. In the 19th century, Hugo Schiff recorded the first synthesis of Schiff bases (imines). A Schiff base is considered as an aldehyde with a C=N group (azomethine group) in steed of the C=O group, It is normally produced by condensation of primary amines with aldehydes. Schiff bases entertain many important biologically and pharmaceutical activities and they are distinguished for their pharmacological action and wide-range applications in the food industry.This study tries to focus on the green synthetic methods used for Schiff bases synthesis, in order to find the best technique that offers higher yields in shorter time within eco-friendly environment.Conclusions: The review considered many green synthetics techniques, from which the microwaves irradiation method is considered to be the best followed by the ultrasonic, natural acids utilizing and grinding methods.