Patent ID: 6696609
Filing Date: 2004-02-24
Classification: C07C

Abstract:
A process for producing diamines which comprises the steps of:(1) reacting a dialdehyde with ammonia and hydrogen in the presence of an alcohol represented by the following general formula (I) Râ€”OHâ€ƒâ€ƒ(I) wherein R represents methyl group or ethyl group, and a hydrogenation catalyst, to synthesize the corresponding diamine;(2) separating and recovering said alcohol by distilling the reaction mixture obtained in the step (1); (3) separating the diamine by purifying the distillation residue obtained in the step (2); and (4) feeding at least part of said alcohol recovered in the step (2) to the step (1); said step (1) comprising maintaining the amount of ammonia at a level of at least 200 moles per mole of the primary amine represented by the following general formula (II)Râ€”NH2â€ƒâ€ƒ(II) wherein R is as defined above that has formed in the step (1) and accumulated in the reaction vessel for step (1).