08-14-02 09:37
No 345270
Heres a good suggestion for those who like to run the Al.Hg fast and hot. Best peice of glassware i have purchased in a while is a 24/40 male to air inlet adapter. Plug this on the top of your condenser and put a hose on it leading to a flask to catch any over flow - no worries, and once it settels back down you can just return the over flow.
You can use this along with a claisien adapter flask and an addition funnel for a pretty effective gassing station as well.
enjoy.
A nut for a jar of tuna.
-The drive by palindromer
(Hive Bee)
08-14-02 17:27
No 345360
Good idea~!
hcildoduedn
(Stoni's sexual toy)
08-14-02 17:56
No 345365
The hotter you run the Al/Hg, the more methylamine will be lost. Keep the temp just under a steady reflux. It might take from 30 minutes (thin foil) to a few hours (thick sheet) longer. But who cares. Every gram more yield means 6-8 more trips ($$$!). It's worth it!
I'm not fat just horizontally disproportionate.
(Hive Addict)
08-14-02 18:35
No 345373
Man you still haven't learned!
I told you to keep it fucking cool. Not boiling over.... AND I BET YOUR STILL GETTING 8G YIELDS!
Yes, That pic really is me!
(Chef d'Equippe)
08-16-02 17:48
No 345989
Lazy,stupid & reckless. Try running it correctly, thats geyser-proofing.
GODISNOWHERE
Shoot Narcs, Not Drugs
(Philosopher, Stoned)
08-16-02 20:07
No 346017
well everyone seems to have their own opion on the al.hg and im always open for new views. iv read MM pictoral on a slower addition and i have also read bees running it very hot, even with double condensers. What is a bee to do... anyways SWIM ran addition fast, but well controlled with no geyser effect ever occuring and got about 75-80% molar yield.
SWIM has done the al.hg with a many various reaction peramiters as per the suggestions she has heard from other bees, slow addition, fast addition, extermal cooling, and insultation and external heating - even has found that if you chill the solution to much prior to addition, no reaction occurs.
What is the consensus at the moment for the al.hg? what is the accepted to be the current best reaction peramiters?
Thanks so much and happy dreaming
A nut for a jar of tuna.
-The drive by palindromer
(Hive Bee)
08-16-02 20:48
No 346031
I'd do it Osmium style, make your methylamine, but not in situ from nitromethane. It's still exothermic, but nowhere near as much. No geysers. If you're one of the blessed who have 40% aqueous solution, then don't add any extra water.
Roundbottom posted a +90% yield working this way and didn't have any trouble. Search for his posts.
(Stoni's sexual toy)
08-16-02 21:00
No 346033
You can use MeNO2 and still have good yields. The problem is the Al foil. It reacts too fast. The energy is released during a very short time, and that's why people have to use so much solvent. When using thicker Al the reaction will run much more gentle, it won't heat up so fast (but will take longer to complete), it will work with less solvent meaning bigger batches can be done with already existing glassware.
The really clever ones reduce the MeNO2 with Al/Hg in an alcohol solvent, filter the sludge out and use the solvent loaded with MeNH2 for the ketone amination. And once that reaction is done and that sludge is filtered out the MeNH2 containing solvent can again be distilled and reused for future runs. Or you carefully acidify the solvents and evaporate to obtain the MeNH2.HCl. Having a rotovap will speed all this up immensely!
I'm not fat just horizontally disproportionate.
(Newbee)
08-22-02 00:58
No 347484
"reduce the MeNO2 with Al/Hg in an alcohol solvent, filter the sludge out and use the solvent loaded with MeNH2 for the ketone amination"
Done that. Use external heating or it will probably fail. Ive been trying to get yields with MeN02/al/hg by bubbling through MeOH (used dry ice, blah, blah). I really need to weigh the MeOH afterwards but I still wouldn't know the percentage. It sure as hell smells like its strong as it can get. Im guessing ~5% w/w. Of course not as strong as aqueous 40% (smells a fraction of that). Ive tried using this bubbled shit twice and it failed. Possibly bad ketone too. I want to get MeAm HCL by adding HCL dropwise to Meam/Methanol mix and evaporating. I could then do the conversions needed to understand exactly how much Meam freebase is in this MeOH.