Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Triethyl Orthoacetate?
UranylPeroxysulfate
Harmless
*




Posts: 23
Registered: 11-6-2018
Member Is Offline

Mood: Sulfonated

[*] posted on 7-5-2021 at 19:52
Triethyl Orthoacetate?


Hi,

I need triethyl orthoacetate for future synthesis. I plan to make it by dehydrating acetamide with P4O10 to acetonitrile followed by ethanolysis of acetonitrile (I based this procedure on the industrial production of trimethyl orthoformate: methanolysis of hydrogen cyanide).

From what I know, the ethanolysis of acetonitrile can be catalyzed by both acid and base. Since orthoesters are extremely water-sensitive, the acid/base has to be completely water-free.

Here are the methods I came up with:

Acid catalysis:
- Direct ethanolysis with conc. 98% sulfuric acid as a catalyst
- Saturating an ethanol/acetonitrile mixture with anhydrous HCl gas, then reflux to perform the ethanolysis

The problem with acid catalysis is that a stoichiometric excess of acid is required since ammonia is released in the ethanolysis.

Base catalysis:
- Dissolving NaOH or KOH in ethanol, then remove water using molecular sieves. Filter off the molecular sieves, add acetonitrile, then reflux to perform the ethanolysis (I do not have sodium metal, so I have to go with this route).
- Adding lithium metal (from batteries) to ethanol to form lithium ethoxide. After it completely reacts, add acetonitrile, then reflux to perform the ethanolysis.

Which method do you think will work the best?




If something does work, sulfonate it.
View user's profile View All Posts By User
unionised
International Hazard
*****




Posts: 5103
Registered: 1-11-2003
Location: UK
Member Is Offline

Mood: No Mood

[*] posted on 8-5-2021 at 07:21


Adding sulphuric acid to acetonitrile is dangerous.

You may provoke the exothermic trimerisation/ polymerisation. (The same, incidentally, is true with HCN).
https://webwiser.nlm.nih.gov/substance?substanceId=392&i...

HCl seems to be acceptable.

This might help.
https://en.wikipedia.org/wiki/Pinner_reaction



View user's profile View All Posts By User

  Go To Top