Reactions of 1,1-Dimethyl-4-substituted-semicarbazides with Phosgene

Article abstract of DOI:10.1021/jo00266a010

Reaction of excess phosgene with 1,1-dimethyl-4-phenylsemicarbazide, 3, gave 3-chloro-1-methyl-4-phenyl-Δ²-1,2,4-triazolin-5-one, 4.An investigation into the reaction pathway led to the surprising find that when 1 equiv of phosgene was allowed