US Patent 8487134 Process for the synthesis of amphetamine derivatives

The invention relates to processes for preparing acylated amphetamine, methamphetamine and dexamphetamine derivatives by reacting the parent amine with the to be-coupled acid or a salt of the to-be coupled acid which acid is optionally protected, in the presence of an alkylphosphonic acid anhydride as coupling agent and, if the acid was protected then cleaving the protecting group(s), in a one-pot reaction or in two or more separate steps.