Your heating temperature is well enough to make acetic anhydride vapors flammable.
Quote:
Autoignition temperature: 316C (601F)
This is where automatic ignition by heat occurs in a regular atmosphere, I'm not familiar if an oven can allow the vapors to contact something hotter
than the setting heat, which might cause ignition or explosion.
Quote:
Flammable limits in air % by volume:
lel: 2.7; uel: 10.3
Flammable.
This is the upper and lower explosive limit, as long as the values are right on, nothing explodes above or below this level.
Maybe somebody familiar with the mechanics and engineering of an oven could weigh in here, but doesn't sound like a wise idea.Klute - 6-9-2008 at 05:27
A acetylation reaction in a metal plate covered by aluminium? Hardly sounds like aspirin synthesis.. more like cooking (pun intended).
Why not at least try to do it correctly and use some glassware?woelen - 6-9-2008 at 10:28
This entire procedure really sounds like crap to me. Cooking in a kitchen with the wrong ingredients .
Get yourself some decent glassware and do not mess around with pans and Al-foil for reactions, involving acetic anhydride and related compounds. And
somehow I have the feeling that it would be better if the mentioned acetylation is not performed at all.kclo4 - 6-9-2008 at 14:53
What is it you are doing anyways what requires it to be heated in an oven? I'm curious Klute - 6-9-2008 at 15:28
I would venture it to be some kind of di-hydroxylated alkaoid...
Conducter, before considering using DMAP for such acetylations, i would suggest trying to do it correctly, and cleaning your product in a decent
fashion. Cooking some alkaoid, DMAP and Ac2O in an oven is not a healthy thing to do, I don't want to know what you plan on doing with your product
after that.. With such lab technic, anything close to DMAP would be a serious health hazard to you and your friends.
By using a aluminium-covered spoon, you loose part of your anhydride before it reacts (and spoil your oven), possibly introduce aluminium salts in
your product, and loose your product when removing it.
Damn, even a kids chemistry set flask would be much better suited. You have a hotplate, use it. Immerse your flask in a oil bath at the correct temp
for the correct time, remove excess anhydride (NOT by ingniting the damn thing...), and purify your product. At least do it correctly.Sandmeyer - 6-9-2008 at 15:40
Quote:
Conducter, before considering using DMAP for such acetylations
When did he mention using DMAP?
[Edited on 6-9-2008 by Sandmeyer]Klute - 6-9-2008 at 16:06
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