Novel reactions of diazonium salts: direct conversion of o- and p-chlorobenzenediazonium acetates into hydroxybenzenediazonium salts, of o-acetoxybenzenediazonium acetate into the carbene, 2-oxocyclohexa-3,5-dienylidene, and of o-thioacetoxybenzenediazonium acetate into 1,2,3-benzothiadiazole

Abstract

The presence of 1,1-diphenylethene (1 equiv.) as a radical chain suppressor in decompositions of o- and p-chlorobenzenediazonium acetates formed in situ from the corresponding N-nitrosoacetanilides, in benzene at 50 °C, promotes previously unobserved ionic displacements of chloride by acetate, followed by deacetylation to give, for example, clean precipitation of p-hydroxybenzenediazonium chloride; extension of the reaction leads conveniently to the generation of 2-oxocyclohexa3,5-dienylidene from N-nitroso-o-acetoxyacetanilide and of 1,2,3-benzothiadiazole from N-nitroso-o-thioacetoxyacetanilide.