Methyl ( E )‐2‐(1‐Aryl‐4,5‐dihydro‐1 H ‐tetrazol‐5‐ylidene)‐2‐cyanoacetate from Methyl 3,3‐Diazido‐2‐cyanoacrylate and Primary Aromatic Amines

A 1,5′ ring closure to give 3 and N 2 elimination accompanied by nitrene addition to the CC bond to give 4 –these are the reaction possibilities available to vinyl azides 2 if the substituent at the 4 position is an NHR′ group that can become involved in the reaction. Previously, only 1,5 and 3,5 ring‐closure reactions were known for vinyl azides substituted at the 4 position with donor groups. The azides 4 are easily prepared from the methyl cyanoacrylate 1 and primary aryl amines.