Sciencemadness Discussion Board

Probably not triethyl phosphate

Prepic - 10-8-2019 at 09:49

Hi all,

I was reading around the internet on various things I want to make and I came across a site called "Gluon's lab".

What caught my eye is the proposed synthesis of triethyl phosphate using phosphoric acid, conc. hydrochloric acid and ethanol.

As far as I know, that esterification should be impossible. I've google around and cant find any reason to believe it. That said, is there any sort of reaction with those three reagents?

Gluon's lab link: http://agedspoonchemistry.blogspot.com/2015/11/making-trieth...


icelake - 10-8-2019 at 10:51

https://patents.google.com/patent/US3331895

There are various different methods for preparing lower dialkyl phosphites and lower trialkyl phosphates. A difficulty confronted in these processes is in the removal of hydrogen chloride and alkyl chloride by-products formed during the reaction by which the esters are made from alcohol and chlorine-containing phosphorus compound. If these by-products are allowed to remain in contact with the reaction product, various side reactions take place which decrease the amount of desired product recoverable. For example, if hydrogen chloride is allowed to stay in contact with a lower dialkyl phosphite, the monoalkyl phosphite is formed with eventual degradation to phosphorus acid or chlorides thereof. The presence of hydrogen chloride during the preparation of trialkyl phosphates is also detrimental to the process, due to side reactions. In this instance, the trialkyl phosphate will be degraded to dialkyl phosphate. Heat has also caused the side reactions set forth above to be accelerated. In fact, the heat of reaction alone is even known to cause degradation of the products.

[Edited on 10-8-2019 by icelake]

[Edited on 10-8-2019 by icelake]