Same principle for triethylamine... Won't work either!
You need either methylamine og nitromethane to make MDMA from MDP2P... Nothing(probably) else will work(for the direct route that is).
The tertiary amines are never used for substitution reactions like that, because the simply don't react that way. All of their available electron sites are taken by the alkyl chain. The only thing left are the lone pair, which you wont get to react
The tertiary amines are often used as a pseudo-inert base, as they wont react with stuff like methyliodide and the like, but still can scavange for some H+ and make a quatinary salt.
Regards
bandil