Ring Contraction of 4-diazo-1-phenyl-5,6-dioxo-1,4,5,6-tetrahydropyridazine in the Solid State Via ʺpyrazolo-lactoneʺ

by Branko Stanovnik, Miha Tišler, Jernej Bradač, Bojan Budič, Božidar Koren, Bojana Mozetič-Reščič · 1979