It is a well known process to reductively aminate a ketone with a primary amine to form a secondary amine with aluminum amalgam. An example would be MDP2P aminated with methylamine and reduced to form MDMA.

To what extent would the reaction of MDMA with MDP2P to form an quaternary imine, followed by reduction to the corresponding high m.w. tertiary amine, occur? It seems to me that this sidereaction would be minimized due to steric hindrance, but, of course, that is only conjecture.

The intermediate wouldn't be too favorable considering it would have a + charge on the nitrogen, as well is being very hindered.