Synthesis of 5-[1-aryl-pyrrol-2-yl]-1H-tetrazole

In this paper, tetrazole ring systems were sythesized by using readily available materials via anodic cyanations of suitably N-substituted pyrrole as key step. The electrooxidation of several 1-arylpyrroles was carried out in methanol containing sodium cyanide at a Pt anode in a divided cell. In all instances, replacement of a heteroaromatic hydrogen by a cyano group occurred regio-selectively. The corresponding pyrrole cyanides were obtained in yields ranging from 76 to 85%. The advantages of electrochemistry synthesis of pyrrole cyanides are as follows: the reaction condition is simple, the cost is low and the products is highly pure. The new tetrazole derivatives which may be non-peptidic compounds with I potential angiotensin U antagonist properties, were synthesized by the formal [2 + 3] cycloaddition of NaN3 and pyrrole cyanides.