guyincognito (Hive Bee)
08-15-02 03:35
No 345514
      Methanol distillation (vacuum)?  Bookmark   

In methanol removal (distil) step right after the 36 hr spin in th cyano/amm acetate/ketone rxn. (this is the step that leave you with a whiteish jello sludge when the methanol is gone)

should one vacuum distill the methanol off?  Swim was reading TS2 and it said to vacuum distill in this step, but swim couldn't figure why?

Could it hurt the product?  to go only to like 60-65 C?
(Hive Bee)
08-16-02 07:38
No 345910
      anyone?  Bookmark   

(Chief Bee)
09-02-02 18:22
No 351838
      vacuum or simple distillation in solvent removal  Bookmark   

Vacuum in removal of solvents is mostly used because it is way faster than atmospheric distillation. Just distill as usual when removing solvents, as long as you aren't removing high-boiling solvents as DMF or such things the extra heat applied compared to if you would have used vacuum usually makes no difference to your product.
(Hive Addict)
09-03-02 14:49
No 352243
      Vac distill methanol?  Bookmark   

Vac distill methanol?One needs a good condenser to condense methanol vapours at 760mm already,under vac it seems to be impossible,unless ya have tha dry ice condenser.

A friend with speed is a friend indeed
(Chief Bee)
09-03-02 15:23
No 352249
      Either that, or you use an aspirator, where you ...  Bookmark   

Either that, or you use an aspirator, where you don't need to care about condensing all the methanol.
(Official Hive Approximator)
09-03-02 15:31
No 352252
      another alternative.  Bookmark   

or, if you have one, you could use your chemical resistant membrane pump
and condense "behind" the pump.

(this is especially good if you don't want to polute your waste water with
halogenated or otherwise nasty solvents.)

couch terrorist