nitrous351 (Hive Bee)
07-30-03 10:29
No 450725
      help with Al/Hg nitro  Bookmark   

SWIM needs an answer from someone who has successfully run this rxn at half-scale. MM recommends using a 400mm column to contain the refulx...SWIM is running the rxn at half scale, so will a 200mm column suffice to contain the reflux, or will SWIM need a bigger column? Or, alternatively, could SWIM use a 200mm vigreux column with a 200mm condenser stacked on top?
PLEASE!!! only people who have successfully done this rxn respond! SWIM doesn't want "I think" or "maybe"
SWIM doesn't want to sound like an asshole, but he also doesn't want hot aluminum amalgam spewing all over himself and the lab.
SWIM would like to thank everyone in advance for the help! peace

D.A.R.E. = Drugs Are Really Exciting
(Hive Addict)
07-30-03 11:47
No 450734
      addition rate  Bookmark   

if you're worried, then run it slow.  slow the addition rate, and that will reduce the amount of cooling necessary.

stack the condensers, run their cooling seperately, not in serial (ie, DO NOT link the output from one condenser to the input of the next).

Now with 12% more Bottom!
Nymphomania is not a disease, its a goal! (Methadist)
(Hive Bee)
07-30-03 19:40
No 450787
      I've Run This Half Scale  Bookmark   

Full Scale and Double Scale. No matter what scale you run it, this is one HOT exothermic reaction so the more cooling the better! Even at half scale, I'd use as BIG a reflux condensor as possible.
Follow the directions: drip in the nitro so that you have a very strong reflux; i.e. the methanol should be dripping down from condensor like rain. If your heart ain't beating fast, the reflux isn't strong enough!
As long as you're circulating ice-COLD water thru the condenser,  and not dripping in the nitro faster than say 2 drops per second, it's not gonna meltdown. I've crapped my pants a few times but never had the reaction volcano or explode....
(Chef d'Equippe)
07-31-03 03:05
No 450854
      The size of the flask actually will make more...  Bookmark   

The size of the flask actually will make more of the difference than condenser size in this case. I would recommend 3L+ for a full 25-30g run. The headroom is most important(condensers as well) when you start increasing the reaction size. Just use common sense, youve said you have already run a 1/2 scale....

Shoot Narcs, Not Drugs
07-31-03 06:17
No 450889
      What about freezer cold methanol?  Bookmark   

What if someone was to drip in the nitro in chilled methanol(-20) the flask being in an ice bath?. Wouldnt that help  in this case to keep more methylamine in the mix?
I have always wondered why we need to run it hot, what difference does it make? Does it favor the imine formation or reduction? What if that was done as cool as possible?
Anybody have an opinion?
(Hive Bee)
07-31-03 11:07
No 450926
      I Agree with Baalchemist  Bookmark   

I traded in my 2 liter flask for a 3 liter one to run the Al/Hg reactions in. Definitely gives more "breathing" space.