Synthesis of Some Unsymmetrical Dioxime Esters Using the Acetylacetone as a Precursor

Three unsymmetrical dioxime esters (2E,4E)-(4-imino O-benzoyl-2-imino O-terphthaloyl)pentane, (2E,4E)-(4-imino O-benzoyl-2-imino O-tosyl)pentane and (2E,4E)-(4-imino O-terphthaloyl-2-imino O-tosyl)pentane were obtained employing esterification process between (2E,4E)-pentane-2,4-dione O4-benzoyl dioxime 2 and terephthaloyl chloride or tosyl chloride. The third unsymmetrical dioxime ester was synthesized through similar esterification reaction between 4-(2E,4E)-4-(hydroxyimino)pentan-2-ylideneaminooxycarbonyl)benzoyl chloride 8 and tosyl chloride. The yields of these esterification reactions has been found to vary from moderate to very good yields giving single geometric isomers in all cases. The synthesis of these three unsymmetrical dioxime esters required, firstly, the synthesis of (2E,4E)-pentane-2,4-dione O4-benzoyl dioxime and 4- [(2E,4E)-4-(hydroxyimino)pentan-2-ylidene]amino oxycarbonylbenzoyl chloride as two precursors.