SYNTHESIS OF R(2)N-R' DISSYMMETRIC AMINES FROM NITRILES AND HEXAMETHYLENETETRAMINE OVER NICKEL-CATALYSTS

The synthesis of methylated tertiary amines (RN(CH3)(2) or R(2)NCH(3)) was carried out at low pressure and temperature (P=0.1 MPa, T less than or equal to 160 degrees C) from fatty nitriles, hydrogen and hexamethylenetetramine (HMTA) over a nickel catalyst. HMTA, the methylating agent, is both very reactive and selective with the final selectivity depending on the experimental conditions. Indeed, over the same nickel catalyst, methyldidodecylamine is selectively obtained at 80-100 degrees C while at 140-160 degrees C dimethyldodecylamine is the main product starting from dodecylnitrile. These products would result from the reactions of didodecylamine or of dodecylamine (issued from the hydrogenation of dodecylnitrile) with methylimine (CH2=NH) or with N-methylmethylimine(CH3-N=CH2) formed from the catalytic decomposition of HMTA.