Alkylation 392 Carbylamine reaction

The versatility of this method for the alkylation of compounds containing active methylene groups is illustrated by Table I. Review articles have recently appeared,34 and the application to the Hofmann carbylamine reaction is described in the following procedure in this volume, p. 96. 

Similarly, reaction of enamines such as 218 with benzotriazole affords a-aminoalkyl-benzotriazoles 219, which react smoothly with organomagnesium compounds, giving tertiary alkyl carbylamines 220 (equation 149) . The whole sequence can therefore be considered as the addition of Grignard reagents to imines. 

The realization that this was a new type of compound, isomeric to the nitriles, and the elaboration of the classical methods for the preparation of isocyanides, the alkylation method and the carbylamine method by Gautier and Hofmann, initiated an active period of isocyanide chemistry that ended by the turn of the century with Nef s investigations on the reactions of the formally divalent carbon atom in the isocyanides. - TTie discovery of the Passerini reaction in 1921 led to a brief renaissance of isocyanide chemistry. 

When an alkyl halide is treated with silver cyanide, reaction takes place in the usual way a silver halide and an organic compound are formed. The product, however, is not an alkyl cyanide, as is the case when potassium cyanide is used, but an isomeric compound. The substances prepared from silver cyanide are called isocyanides, isonitriles, or carbylamines. The last name is given to them on account of the fact that they unite with acids and thus resemble the amines. The addition-products do not, however, resemble salts in their chemical properties. When hydrogen chloride is passed into an ethereal solution of methyl isocyanide, a compound of the formula 2CH3NC.3HCI is formed, which is decomposed when brought into contact with water. 

---