Process for preparing higher purity azo compounds
AssigneeE. I. Du Pont de Nemours and Company
InventorsRichard N. Knowles, Earl P. Moore, Jr.
Life of this patent
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Abstract
After an azonitrile is prepared by coupling an aminonitrile in the presence of a hypochlorite, the reaction mixture is acidified to a pH of 4 or less and an alkali metal, alkaline earth metal or quaternary ammonium nitrite, sulfite, bisulfite or thiosulfate, sulfur dioxide, nitrogen oxide, oxalic acid, formaldehyde or hydroxylamine is added as a reducing agent.
Claims9
In a process for producing an azonitrile by coupling an aminonitrile in the presence of a hypochlorite, the improvement which comprises acidifying the reaction mixture to a pH of a maximum of 4 and adding an alkali metal nitrite, alkali metal sulfite, alkali metal bisulfite, alkali metal thiosulfate, alkaline earth metal nitrite, alkaline earth metal sulfite, alkaline earth metal bisulfite, alkaline earth metal thiosulfate, quaternary ammonium nitrite, quaternary ammonium sulfite, quaternary ammonium bisulfite, quaternary ammonium thiosulfate, sulfur dioxide, nitrogen oxide, oxalic acid, formaldehyde or hydroxylamine as a reducing agent after the coupling reaction is completed.
Dependencies are inferred from the claim text.