N-Alkylation of sulfonamides by alkyl halides in the presence of electrophilic catalysts and transformations of alkylated compounds

• Main Authors: Larysa V. Dmitrikova, Svetlana D. Kopteva, Victor I. Markov
• Format: Article
• Language: English
• Published: Oles Honchar Dnipropetrovsk National University 2016-12-01
• Series: Vìsnik Dnìpropetrovsʹkogo Unìversitetu: Serìâ Hìmìâ
• Subjects: aryl sulfonamides; alkyl sulfonamides; sulfonyl aziridines; Lewis acids
• Online Access: http://chemistry.dnu.dp.ua/article/view/77519
• ISSN: 2306-871X; 2313-4984

Vicinal halo amines constitute an important class of compounds due to their diverse biological activity and a broad application as synthones in the production of pharmaceutical agents. The reaction of aryl- and alkylsulfonamides with 1,2-dibromo-2-phenylethane in the presence of Lewis acids (such as FeCl₃ and ZnCl₂) in 1,2-dichloroethane can represent one of the most efficient ways of halo amine synthesis. It has been shown that methanesulfonamides and benzylsulfonamides starting materials produced the alkylation products with good yields while <em>p</em>-toluenesulfonamides appeared to be less active and 6-methyl-3-nitrobenzylsulfonamides did not give the expected compounds. It has been found that synthesized vicinal halo amides can easily cyclize in alkaline conditions to give 1-sulfonylaziridines. The regioselectivity of aziridine ring opening has also been studied. It was established that strong nucleophile attacks terminal carbon which leads to the breaking-up of 1–3 bond and subsequent aziridine ring opening. In contrast, weak nucleophiles (water, potassium rhodanide, hydrogen bromide) trigger the cleavage of aziridine cycle by breaking-up of 1–2 bond under acidic conditions which is in accordance with molecular orbital theory. Substituents at the aromatic ring of sulfonyl fragment do not influence on the pathway of aziridine ring opening.