The Evaluation of Some Heterocycles as Antioxidant Additives for Lubricating Oils

Abstract

2-Phenyl-4-thienylidene-2-oxazolin-5-one I was prepared and reacted with 2-aminothiazole, p-aminophenol, and p-aminoacetophenone in the presence of acetic acid containing catalytic amounts of freshly fused sodium acetate to give the corresponding imidazolone derivatives II, III, and IV, respectively. A Claisen reaction of IV with ethylacetate gave the corresponding imidazolone V, which on reaction with phenylhydrazine in ethanol afforded the corresponding pyrazolinoimidazolone VI. On the other hand, I reacted with o- and p-phenylenediamines in ethanol and yielded the corresponding o- and p-aminophenylcarboxamide of α-phenyl carboxamido-β-thiophenoacrylic acids VII and VIII, respectively. The prepared products were evaluated as antioxidant additives for Egyptian lube oils. Some of these products showed good results.