IR and UV spectroscopy were used to assign structures to diazoniumcouplingproducts V-VII of ethyl p-toluenesulfonylacetate, benzenesulfonylacetophenone and benzenesulfonylacetanilide. The data have established that such couplingproducts exist largely as chelated hydrazones. An alternative synthesis of couplingproducts V and VII from the corresponding arylhydrazidic chlorides and sodium arenesulfinate