Reduction of Nitrosamines with Aqueous Titanium Trichloride: Convenient Preparation of Aliphatic Hydrazines

Article abstract of DOI:10.1021/jo00193a007

The reduction of selected nitrosamines by aqueous TiCl3 has been investigated.In general, aliphatic nitrosamines were converted in good yield to the corresponding hydrazines, with little overreduction to the amines.Reaction proceeded rapidly at room temperature in both alkaline and acidic media.A variety of N,N-dialkylhydrazines have been isolated by using the TiCl3 method, which compares favorably with previously reported procedures for preparatively converting nitrosamines to hydrazines.In the reduction of N-nitroso-N-methylaniline, the proportion of amine in the product increased significantly as the pH of the reaction mixture was lowered, presumably reflecting the known instability of arylalkylnitrosamines in strong acid, coupled with a ready reducibility of the corresponding Fischer-Hepp intermediates; some tendency toward reductive cleavage of the N-aryl-N-alkylhydrazine's N-N-bond was also noted.Reduction of an α-nitrosamino ether gave the monoalkylhydrazine as the major product, while all other reducing agents studied converted this starting material chiefly to a mixture of primary and secondary amines.