Reactions of β‐Azolylenamines with Sulfonyl Azides as an Approach to N ‐Unsubstituted 1,2,3‐Triazoles and Ethene‐1,2‐diamines

The reactions of β‐azolylenamines 1 with sulfonyl azides 2 in acetonitrile furnished 1 H ‐4‐(azol‐5‐yl)‐1,2,3‐triazoles 3 in yields of 52–93 %. β‐Benzoylenaminones and β‐nitroenamine of type 1 also reacted with tosyl azide to form the same type of products 3 , proving the generality and efficiency of the method for the synthesis of N ‐unsubstituted 1,2,3‐triazoles. On the other hand, the reactions of 3‐(1‐aryl‐1,2,3‐triazol‐5‐yl)enamines with tosyl azide in the absence of a solvent afforded a mixture of ( E )‐1‐dimethylamino‐2‐tosylaminoethenes 5 and N , N ‐dimethyl‐ N′ ‐tosylformamidine 6 in yields of 40–50 and 20 %, respectively. The formation of a variety of compounds from the reactions of enamines 1 with sulfonyl azides 2 is rationalized by the various possible transformations of the intermediate 5‐dimethylamino‐1,2,3‐triazolines 7 .