Addition of Nitrile Oxides to Allyl Esters of Aryl(hetaryl)carboxylic Acids

3,5-Disubstituted isoxazolines with an aryl(hetaryl)carboxymethyl group in position 5 have been synthesized. The addition reaction of nitrile oxides to allyl esters of aryl(hetaryl) carboxylic acids occurs regiospecifically with the formation of the 5-substituted isomer. Initial pharmacological screening showed that 5-(4-bromobenzoyloxy)methyl-3-(3,4-dimethoxyphenyl)isoxazoline possesses marked nootropic activity.