Catalyzed nitration of amines; the role of electropositive chlorine in the nitration of lysidine

The nitration of lysidine with acetic anhydride, nitric acid, and a chloride catalyst does not yield the expected nitrolysidine. The product, instead, is 1,3-dinitroimidazolidone-2 when little or no chloride is used. A new compound is produced when a full equivalent of hydrogen chloride is included. This new compound is thought to be 1,3-dinitro-2-chloromethyl-2-acetoxylimidazolidine. Its decomposition products are ethylenedinitramine and chloroacetic acid. It is believed to be cyclic because the linear isomer, N-acetyl-N′-chloroacetylethylenedinitramine has been prepared and found not to be identical. The formation of dinitrochloromethylacetoxylimidazolidine in the nitration mixture suggests that it is formed by addition of chlorine acetate. This compound has been prepared, characterized, and found to add to allylbenzene. Since it will convert dicyclohexylamine to the chloramine it is postulated as a temporal ingredient of the catalyzed nitration mixture.