4-Phenylurazole CAS NO.15988-11-1

4-Phenylurazole undergoes oxidation in the presence of NO2-N2O4 to yield 4-phenyl-1,2,4-trizoline-3,5-dione. It undergoes acetylation reaction with excess acetyl chloride in N,N-dimethylacetamide solution. It polymerizes in the presence of phosgene, terephthaloyl chloride and epichlorohydrin to yield insoluble polymer. It is precursor to the Diels-Alder trapping agent, 4-phenyl-1,2,4-triazoline-3,5-dione. This urazole was recently demonstrated in the traceless, chemoselective labeling of peptides and proteins through electrochemical tyrosine-click (e-Y-CLICK) chemistry.