Structural studies on bioactive compounds. Part 31. Interaction of 9-azidoacridine and 1-morpholinocyclohexene: formation, decomposition and rearrangement of the intermediate 1,2,3-triazoline

9-Azidoacridine 1 and the cyclic enamine 2 undergo a selective 1,3-dipolar cycloaddition reaction to give the 1,2,3-triazoline 3 with the expected reg iochemistry. Exposure of the triazoline 3 to methanol induces the extrusion of nitrogen accompanied by a ring contraction to furnish the amidino-acrid ine 5 in high yield.