Facile synthesis of 1,2,4-oxadiazoles by the cycloaddition of N-hydroxybenzenecarbonimidoyl chlorides and nitriles under mild conditions

We report a mild synthesis of 1,2,4-oxadiazoles via the dipolar cycloaddition of N-hydroxybenzenecarbonimidoyl chlorides with nitriles under metal-free and catalyst-free conditions. We demonstrate a wide-substrate scope with aryl, heteroaryl, and alkyl substituents on both substrates with up to 91% yield.