Rahul - 16-11-2002 at 04:54
Hello everyone
In the ketene process, Acetic acid is cracked to Ketene in the presence of triethl phosphate (TEP). I beleive, it was also possible in the past with
phosphoric acid as a substitute for TEP. What are the obvious reasons to choose TEP ...reciprocating the fact the TEP is way more expensive compd to
phosphoric acid. Secondly when Ammonia is added to stop the catalytic activity of TEP, then what is the underlying chemistry ? does TEP dissociates to
phosphoric acid and which eventually reacts with NH3 to produce diammonim salt of phosphate ?
If so, do we need cautic treatment to get rid of these salts ? and again what is the chemistry involved ?
TEP
The_Grid - 16-11-2002 at 06:21
Triethl phosphate can be used as a multiple catalyst
to produce for instance
X-fluoro-Y,Z-ethylaniline and phosphate-salt
in presence of acetic acid/anhydride and alcaloides.
Well known procedures are catalyst-mixtures of
TEP/acetic acid and charcoal/palladium.
ps.
E&W are closed for not registered users !
Whats the fuck after 2-weeks opening ??? 
Rahul - 17-11-2002 at 12:53
thanks for the reply dude ...can you provide me the references about the clues rendered by you and bit more specific ?
PS:
I've no idea what you really mean by those lines......I'm a registered user
no quirks though 
Polverone - 17-11-2002 at 20:40
If you want to produce ketene, I don't know why you need TEP or phosphoric acid. Did you pick this up from some industrial process? On a lab scale,
you can produce ketene in 90% yields from pyrolysis of acetone. See the 3rd edition of Vogel for details.