Synthesis and characterization of new oxazole containing compounds

Abstract

4-Chloro-2,5-diphenyloxazole was synthesized from the reaction of benzoyl cyanide with benzaldehyde and gave the yield 67%. The mechanism of 4-chloro-oxazole formation was proposed to occur via acylimidoyl chloride intermediate. Similarly, reaction was used for the synthesis of 1,4-bis(4-chloro-5-phenyloxazol-2-yl)benzene and 1,4-bis(4-chloro-2-phenyloxazol-5-yl). These compounds have been synthesized by reacting between benzoyl cyanide and terephthacarboxaldehyde, and terephthaloyl cyanide and benzaldehyde, respectively in dried diethyl ether and saturated with hydrogen chloride gas that gave the yield 59% and 52%, respectively. The reduction of 1,4-bis(5-phenyloxazol-2-yl)benzene or POPOP can occur via catalytic hydrogenation employing 10% Pd/C as catalyst. All these products were identified by the spectroscopic techniques. The synthesis of oligomer containing oxazole moiety in the backbone was also attempted. The optical property of these compoundsin various solvents had been investigated. It was found that 1,4-bis(4-chloro-5-phenyloxazol-2-yl)benzene and 1,4-bis(4-chloro-2-phenyloxazol-5-yl)benzene gave higher fluorescence quantum yields than 4-chloro-2,5-diphenyloxazole.