The Sommelet Reaction

Angyal, S. J.


The Sommelet reaction is the process whereby aldehydes are produced from alkyl halides by the action of hexamine. The reaction is essentially a conversion of an amine into an aldehyde, a process in itself that is not particularly useful because aldehydes are frequently more readily available than the corresponding primary amines, It is fortunate therefore that the required amines can be prepared by the interaction of alkyl halides with hexamine, i.e., with the same reagent that serves to convert the amines into aldehydes, It is this combined form that was discovered by Sommelet.

The Sommelet reaction, when started with a halide, proceeds in three stages: (1) formation of a hexaminium salt; (2) hydrolysis of this salt to an amine and its methylene derivative; and (3) formation of an aldehyde (the Sommelet reaction proper).