ABSTRACT
The 2-methyl glutaronitrile is obtained as a by-product of the important adiponitrile production. It, nevertheless, gives rise to interesting chemical transformations. In particular, its hydrogenation can produce 2- methylpentanediamine, a substitute to hexamethylenediamine in polyamide or polyurethane compounds. The 3-methylpiperidine, also produced by hydrogenation of 2-methyl glutaronitrile, can be an interesting intermediate for β- picoline production involved in the synthesis of PP vitamin. Using Raney nickel as the catalyst, hydrogenation reactions were performed in various liquid phase compositions. 2-Methylpentanediamine was obtained very selectively. The reaction product can be used itself as solvent. Addition of dry ammonia in ethanol in the place of isopropanol / KOH or NaOH medium leads to a mixture of 2-methylpentanediamine, 3-methyl piperidine and some heavy by-products. This mixture can be cyclized and dehydrogenated to p-picoline (3-methyl pyridine) on a special and very efficient Pd/SiO2 catalyst. The two processes have been patented by Rhône-Poulenc.
