Author Topic: trifluoroacetic anhydride  (Read 2676 times)

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dilaudid

  • Guest
trifluoroacetic anhydride
« on: July 17, 2001, 08:51:00 PM »
One method for taking lysergic acid to LSD uses trifluoroacetic anhydride which can be found in CA 50,10803d 1956. Anywho, my query is about how one would make this stuff. It seems logical that it would come from TFA acid which is more bountiful. In my present local. I have minimal accsess to nice science papers.

Any tips on anhydride synthesi??

foxy2

  • Guest
Re: trifluoroacetic anhydride
« Reply #1 on: July 19, 2001, 02:31:00 PM »

slappy

  • Guest
Re: trifluoroacetic anhydride
« Reply #2 on: July 20, 2001, 01:09:00 AM »
I suppose that you could substitute Trifluoroacetyl Chloride or Sodium Trifluoroacetate in the above synth.

halfapint

  • Guest
Re: trifluoroacetic anhydride
« Reply #3 on: July 20, 2001, 12:05:00 PM »
This synthesis relies on forming the mixed anhydride of lysergic and trifluoroacetic acid. This mechanism would not bee served by use of trifluoroacetyl chloride, nor sodium trifluoroacetate. However, since the most direct technique for the production of trifluoroacetic anhydride is by mixing trifluoroacetyl chloride and sodium trifluoroacetate together, and producing table salt, this suggestion does have an indirect merit. I wouldn't mix them in the presence of a precious and delicate substance like lysergic acid, certainly, but beforehand.

This synthesis was never among my favorites, even when it was new. Trifluoroacetic acid at the time was the strongest organic acid, and AFAIK still may have that distinction. With the anhydride, we're talking some seriously nasty shit. Also the reaction solvent, to my best recollection, is liquid ammonia. For a long time I thought this alone, put it out of reach, but we are among Birch cooks who routinely operate using this solvent, which has forced me to revise my earlier opinion. Not enough to make me like the synth, though.


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