Synthetic approaches of medicinally important Schiff bases: An updated Review

The Schiff base defined by an imine or azomethine (-CH= N-) group, is mostly synthesized by the condensation reaction of carbonyl compounds (Aldehyde or Ketone) with compounds consisting of amine moiety. Schiff bases are among the most chiefly used organic compounds, revealing a wide range of applications, such as electroluminescent effects, fluorescence properties, nonlinear optical and chemosensory properties. The typical Schiff bases are crystalline solids that are basic, although at least some of them combine with strong acids to generate insoluble salt. Schiff bases are widely used in the pharmaceutical, electronic, cosmetic and polymer industries. Schiff bases use various alpha-amino acids and aldehydes in acidic or basic conditions. Schiff bases form a new class of drugs that can strengthen the immune system and also be used in the treatment of various ailments. The C=N imine bond's electrophilic carbon and nucleophilic nitrogen offer great binding chances with many nucleophiles and electrophiles, which can be used to suppress specific diseases, enzymes or DNA replication. These Schiff bases are synthesized from various aldehydes or ketones and amines under stirring conditions, catalyst-free, reflux conditions, conventional methods, microwave irradiation and ultrasonic conditions. Thus, Schiff bases and their derivatives can be synthesized using various techniques and may be further used for enormous biological applications with potent effects.