Chalcones as sythons for heterocyclic compounds- a review

Chalcones are α, β-unsaturated ketones derived from acetate and Shikimic acid pathways, used in the biosynthesis of flavonoids and isoflavonoids. 1,3-diphenyl-2-propen-1-one is the simplest member of the chalcone series, with the molecular formula C15H12O, molar mass of 208.26g/mol, and a melting point of 55-57oC. Chalcones are synthesized by Aldol Condensation reaction using Claisen-Schmidt method which involves reacting equal molar ratios of benzaldehyde and acetophenone in an alcoholic base or their substituted derivatives. The presence of α, β unsaturated ketone makes chalcone a versatile molecule for the synthesis of heterocyclic compounds through reaction with a bi-nucleophile such as hydrazine, urea, guanidine or o-phenylenediamine, to afford five, six or seven membered heterocyclic compounds such as pyrazoles, pyrimidones, pyrimidines, 1,5-benzodiazepines, and1,5-benzothiazepines. Heterocyclic nuclei are present as core structural components in an array of drug categories, such as anti-inflammatory, antihypertensive, antiepileptic, antidepressant and antimicrobial agents. Many chalcones could be used as lifesaving agents because of their immense pharmacological activities, such as antibacterial, antimalarial, antioxidant, anti-HIV and antitumor activities. Thus, they continue to enjoy lots of attention from researchers in the field of drug discovery.