Forster–Decker method

The Forster–Decker method is a series of chemical reactions that have the effect of mono-alkylating a primary amine (1), forming a secondary amine (6). The process occurs by way of transient formation of an imine (3) that undergoes the actual alkylation reaction.



Process stages

 * 1) Conversion of the primary amine to an imine (Schiff base) using an aldehyde.
 * 2) Alkylation of the imine using an alkyl halide, forming an iminium ion.
 * 3) Hydrolysis of the iminium, releasing the secondary amine and regenerating the aldehyde.

Because the actual alkylation occurs on the imine, over-alkylation is not possible. Therefore, this method does not suffer from side-reactions such as formation of tertiary amines as a simple SN2-type process can.