Thermal Decomposition of 1, 3-Diaryl-1-nitrosoureas in Benzene

Abstract

Thermal decomposition of several 1, 3-diaryl-1-nitrosoureas (Ia-e) in benzene gave denitrosated 1, 3-diarylureas (IIa-e), benzene derivatives (IIIa-e), biphenyls (IVa-e) and newly formed 1, 3-diarylureas (Va-e). Based on these results, pathways of the decomposition are proposed. Compounds Ia-e rearrange to the corresponding arylazo arylcarbamates (VIa-e), which decompose to give such intermediates as diazonium ions (VIIa-e), arylcarbamate anions (VIIIa-e) and aryl isocyanates (IXa-e). These intermediates further react with the solvent or other species to give the final products. The existence of these intermediates was confirmed by chemical and spectral studies.