Photochemical Nitrogen Extrusion of 5-Amino-1-vinyl-4,5-dihydro-1H-1,2,3-triazoles. Formation of Unusual Pyrroles

Abstract
Photolysis of 4-alkyl-5-ammo-1-vinyl-4,5-dihydro-1H-1,2,3-triazoles gave not 3-alkylpyrroles, but unexpected 2-alkylpyrroles in 80–83% yields. 1-Vinylaziridines were assumed as a possible intermediate of this unusual pyrrole formation. In the photolysis of 7a-morpholino-1-styryl-3a,4,5,6,7,7a-hexahydro-1H-1,2,3-benzotriazole, however, nitrogen extrusion did not occur, but trans-cis isomerization took place.