Synthesis and characterization of some new quinoline-2-one, schiff bases, pyrazole and pyrazoline compounds derived from hydrazide containing isoxazoline or pyrimidine cycles

Abstract EN

The work involves synthesis of new quinolin-2-one Schiff bases (XIII)a,b and (XIV)a,b, pyrazoles (XI)a,b and pyrazolines (XII)a,b derivatives containing isoxazoline or pyrimidine cycle starting with chalcones.

3-Aminoacetophenone was reacted with 4-bromobenzaldehyde or 4-N,N-dimethyl aminobenzaldehyde in basic medium to give chalcones (I)a,b by Claisen-Schemidt reaction.

These chalcons were reacted with hydroxylamine hydrochloride or with thiourea in basic medium to form isoxazolines (II)a,b or pyrimidine-2-thion (III)a,b ,respectively.Also the pyrimidine-2-thiones (III)a,b and isoxazolines (II)a,b reacted with 4-or 3-substituted benzaldehyde and coumarin to form Schiff bases (IV)a-f (V)a-f and quinoline derivatives (VII)a-d(VIII)a-d, respectively.

On the other hand, compounds (V)b,f were reacted with ethylchloroacetate in basic medium to give ester compounds (IX)a,b .The condensation of new esters (IX)a,b with hydrazine hydrate led to produce new acid hydrazides (X)a,b.The later compound refluxing with 4-substituted benzaldehyde in dry benzene to give Schiff bases (XIII)a,band (XIV)a,b while the reaction of acid hydrazides (X)a,b with acetyl acetone or ethyl aceto acetate led to formation of pyrazole (XI)a,b , pyrazoline (XII)a,b ,respectively.

The synthesized compounds were characterized by melting points, FTIR,C.H.N.analysis, Mass and 1H NMR spectroscopy(of someof them) Some of the synthesized compounds have been screened for their antibacterial activities using two types of bacteria; E.

Coli and Staph.

aureus.

All the examined compounds did not show any biological activity towards E.

Coli but compound (VII)a showed activity towards Staph.

aureus.