Untersuchungen an diazoverbindungen und aziden-LIII : Abfangreaktionen instabiler azomethinimin-dipole mit ethanol

The reaction of the diazo compounds 1a-o with 4-phenyl-1,2,4-triazolin-3,5-dione (2) in dichloromethane-ethanol leads to the urazoles 5a-o; they arise from the primarily formed unstable azomethinhnine dipoles 4a-o by ethanol addition. Acidic hydrolysis of 5k and 5o yields the α-diketones 8 and 10 besides 4-phenyl urazole (9). Bistriazolindiones (13a,b) react analogously with diazo compounds (1l, m) in the presence of ethanol to give the bisurazoles 14a-c.