Sommelet reaction

The Sommelet synthesis is a name reaction in organic chemistry and named after Marcel Sommelet, who described the reaction in 1913 first. Under the Sommelet synthesis refers to the reaction of alkyl halides, especially of benzyl halides with hexamethylenetetramine ( hexamine ) to aldehydes. The reaction is also known under the names: Sommelet reaction, oxidation or Sommelet Sommelet aldehyde synthesis.

Reaction mechanism

The mechanism of the Sommelet reaction was examined more in the course of years. An example, the reaction of benzyl halide was usually regarded with hexamethylenetetramine. For a long time it was assumed that a benzyl amine and a primary imine of formaldehyde arise which then undergoes an intermolecular hydrogen transfer. In this case, then, the primary of the benzaldehyde imine to be created, which is then hydrolyzed to the benzaldehyde. However, target specific formamides as by-products of this conjecture.

Alternatively, the mechanism will be described with reference to the reaction of benzyl chloride with hexamethylenetetramine as follows: In the first step 1 with benzyl hexamethylenetetramine 2 is reacted, by a nucleophilic attack of the nitrogen takes place in the adjacent positively polarized carbon atom of chlorine. The result is a quaternary Hexaminiumsalz 3 The cleaved chloride provides the next step for a deprotonation of the Hexaminiumsalzes. Then, the resulting iminium 4 is hydrolyzed to benzaldehyde is obtained 7.

Itemization

• Name reaction