| Pages:
1
2
3 |
Sauron
International Hazard
Posts: 5351
Registered: 22-12-2006
Location: Barad-Dur, Mordor
Member Is Offline
Mood: metastable
|
|
That is the H.C.Brown article, I believe. Chemrox is well aware of it. It's a good procedure as long as the target acyl chloride is volatile enough
and propionyl chloride certainly is.
I was going to use this method to prepare chloroacetyl chloride, and still might. I have the chloroacetic acid and benzoyl chloride. But I think I
will try the GAA + TCCA method to make chloroacetic acid and then use TCT to get to the chloride. Save the benzoyl chloride for something more
interesting.
Sic gorgeamus a los subjectatus nunc.
|
|
|
ChemPlayer_
Harmless
Posts: 28
Registered: 21-6-2015
Location: Asia
Member Is Offline
Mood: Synthetic
|
|
I tried the Comptes Rendus, 121 1155-6 (1895) method using HCl gas bubbling through chilled acetonitrile and glacial acetic acid.
The gas dissolved in the liquid very readily to the point that I ran out of salt and so didn't even get to see where saturation point was, even using
25% more than the theoretical amount (i.e. 2 x molar equivalents + 25%).
Left overnight the resulting liquid generated pretty snowflake crystals and on distillation the fuming liquid that was decanted off yielded a small
amount (8% based on acetic acid) of acetyl chloride.
So this works but needs some playing around to get a better yield (my first attempt at the reaction so I assume the bad yield is my inexperience
rather than the reaction itself at this stage). Definitely has potential I think as a non-CWC route to acyl chlorides...
The usual video shows the process I followed: https://www.youtube.com/watch?v=Q2ArDw0vf2Q
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
Your video is, as usual, very well presented. Have you seen my similar method?:
http://www.sciencemadness.org/talk/viewthread.php?tid=32991#...
Who owns the sexy female voice of the narrator in your videos? She has such a steady, almost metered, delivery. All her words have a nice lilting
inflection, being almost musical. 
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
ChemPlayer_
Harmless
Posts: 28
Registered: 21-6-2015
Location: Asia
Member Is Offline
Mood: Synthetic
|
|
Yes I saw that - very nice!
It seems relatively easy to convert anhydride to chloride and chloride to anhdride (heat with sodium acetate and then fractionally distill the product
- we tried this and it works ok), but not so easy to get the chloride / anhydride in the first place from other sources without using the usual highly
restricted reagents.
We're also having a play with the sodium pyrosulfate route to the anhydride although actually making even vaguely pure pyrosulfate is extremely
difficult even with accurate temperature control. If this has any success then we'll create a video on this too, but at the moment our instinct is
that it won't be viable.
Why that is Tess, our corporate spokeswoman 
|
|
|
Magpie
lab constructor
Posts: 5939
Registered: 1-11-2003
Location: USA
Member Is Offline
Mood: Chemistry: the subtle science.
|
|
acetic anhydride is a tricky one. It is currently available from the secondary market in the US. However, I understand many countries have it banned
or restricted.
Making it using sulfur halides is feasible for the home chemist. See my procedure in Prepublication. The key to making this a facile procedure is to
use some of the anhydride as a solvent, I believe. So once you have some on hand making it becomes much easier.
Hi Tess!
The single most important condition for a successful synthesis is good mixing - Nicodem
|
|
|
byko3y
National Hazard
Posts: 721
Registered: 16-3-2015
Member Is Offline
Mood: dooM
|
|
Why can't you just use anhydrous acetic acid as initial solvent? Contamination of anhydride with acetic acid is completely acceptable.
|
|
|
ChemPlayer_
Harmless
Posts: 28
Registered: 21-6-2015
Location: Asia
Member Is Offline
Mood: Synthetic
|
|
Magpie, your method intrigues me and makes me wonder if it's possible to produce some aromatic acid chlorides in the same way.
I wonder if phthalic anhydride would react with HCl gas (perhaps molten, or in a solvent system) to produce an acid chloride, or perhaps even a 'half
chloride' (I guess this might convert into the full chloride and phthalic acid).
I will do some experiments with this and see...
|
|
|
| Pages:
1
2
3 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
