Abstract: Processes are described for preparing 2,4-oxazolidinediones having Formula (I) ##STR1## wherein: R.sup.1 is phenyl optionally substituted with 1-2 halogens; or 4-phenoxy, 4-(1-phenethyloxy) or 4-benzyloxy each optionally substituted with R.sup.2 on the phenyl ring; and R.sup.2 is halogen; methyl; or ethyl. 2-Hydroxycarboxylic acid esters are reacted with a carbonylating agent in the presence of a base to give intermediate triazole or imidazole carboxylates. The carboxylates react with phenyl hydrazine in the presence of an acid to give the compounds of Formula (I).

Abstract: Process for preparing aminotriazines wherein it is not necessary to make any separations before completing the preparation. The process of the invention involves reacting dicyandiamides with trimethylorthoacetate in the presence of a catalyst to form aminotriazines.

Abstract: Zwitterionic diazonium salts, derived from aromatic amines, are aggregated by: (a) diazotizing said amine to a zwitterionic diazonium salt in the presence of a cationic surfactant or (b) diazotizing said amine and thereafter treating the resulting zwitterionic diazonium salt with a cationic surfactant, so as to give particles of the diazonium salts which are readily separable from the liquid mass in which they are formed.