Thought I had posted this information, but ok...
An anonymous letter I received reported results from two MM Al/Hg aminations, one at 'normal' (25g ketone) scale in a 2L flask and one at 4x (100g ketone) scale in a bucket. After working up the 25g run (see another post for the gory details), the chemist had some dirty mdma freebase in DCM (although, as stated before, based on most people's standards this would have been considered very clean--yuck).
The letter goes on to say that the chemist judged this amount of mdma freebase insufficient for distillation in the available glassware, so more freebase was sought... thus the 4x scale MM in the bucket. The bucket lid was built pretty much as described in the pics on Rhodium's page, although the chemist reports that finding a shank washer was difficult until he looked specifically in the hardware store's section for replacement toilet parts. Also, the chemist punched another hole in the bucket so the addition funnel could sit in the lid rather than the top of the column. This turned out to be a VERY good idea as the reaction go so hot it literally burped out methanol from time-to-time (burped out of a 40cm condenser sitting on 60cm of vigreux column!).
Based on advice given HERE, the chemist apparently went ahead and tried to stir this reaction with a 3" stirbar on a magnetic stirrer. This was a total failure. DO NOT try and stir this reaction at this size with magnetic stirring. The stirbar just got stuck early on and then there was this pissed off hot reaction to contend with. Not cool. This reaction needs overhead stirring at this scale. The chemist feels his yields were shit because of the lack of stirring. Furthermore, at this scale, this is an ungodly amount of solvent used, waste produced, etc.,. The chemist reports that he will probably *never* run the Al/Hg with nitromethane again ("fuck that", he writes). The workup is just too much of a pain in the ass.
For future runs the chemist has apparently decided to go with Osmium's methylamine Al/Hg.
As far as the low-down dirty details:
The freebase in DCM from the 25g rxn was combined with the freebase in DCM from the 4X 100g reaction, and the lot was then distilled. The chemist recovered 81.5g clean mdma freebase oil, or a 60% molar yield. He thinks had overhead stirring been present the yield would have been much better, but it still would have been a massive pain in the ass to work up (remember, you gotta RECOVER all that toluene and dcm for reuse later).
A watched pot will indeed boil.
