2-Phenylchroman-4-one as synthone in synthesis of new five and six membered rings heterocyclic compounds

Abstract EN

Chroman-4-one derivatives 1(a-i) were prepared by Pechman condensation of phenol or its substitutions with cinnamic acid by using polyphosphoric acid.

These derivatives were reacted with hydrazine hydrate in refluxing ethanol to yield pyrazoline derivatives (2).

The utilityof the Claisen-Schmidt condensation in the synthesis of -3-arylidene-substituted 2-phenyl chroman-4-one 3(a-e) by reaction of proper 4-chromanone (1) with aromatic aldehydes in presence of KOH.

Pyrazolines 4(a-c) were synthesized by the reaction of proper arylidenes 2 with hydrazine hydrate in presence of pyridine.

Finally, the condensation of arylidines with urea gave pyrimidin-2-ones 5(a-d).

The structures of these compounds were confirmed by their physical properties in addition to the IR and UV Spectra.