Synthesis and characterization of novel schiff bases containing isoxazoline or pyrazoline unit

Abstract EN

This work involves synthesis of novel Schiff bases derivatives containing isoxazoline or pyrazoline units starting with chalcone.

4-Aminoacetophenone was react with p-nitrobenzaldehyde or p-chlorobenzaldehyde in basic medium giving chalcone [I]a, b by claisen-schemidt reactions.

The chalcone [I]a, b were reacted with hydroxylamine hydrochloride giving isoxazoline [II]a, b in basic medium.

The chalcone [I]a could also reacted with hydrazine hydrate to give pyrazoline [III]a .

The novel Schiff bases with structural formula [VIII]n , [IX]n , [X]m and [XI]m were prepared by the reaction of amino compounds ; isoxazoline [II]a, b and pyrazoline [III]a with monoaldehydes [VI]n and dialdehydes [VII]m , respectively in dry benzene using drops of glacial acetic acid as a catalyst with reflux .

All the synthesized compounds have been characterized by melting points , FTIR , UV-Vis and 1HMNR (of some of theme) spectroscopy.