Acetyl (Stranger)
11-17-02 09:44
No 380505
      On not forming NAOT  Bookmark   

Another member asked me this question in a PM a while ago, but I seldom ever log on here to check this board.

He wanted to know about forming NAOT from o-toluidine and GAA. He thought I'd know something about acetylation. I suppose it might have had something to do with my nick name and my attempt at making acetic anhydride. (I don't really have a clue about the specific aspects regarding acetylation and never pursued making acetic anhydride)

He said that when he mixed lab grade o-toluidine and lab grade acetic acid that there was a modest generation of heat. He went on to say that after an extended reflux (4hrs) he encountered the same problems as Sky when trying to use GAA and OT to form NAOT. No crystals were present after crashing in cold water and they weren't there even after standing overnight. The aqueous is dark pink, and there's some small blobs of oil. He believes that it all turned into o-toluidine acetate.

A warning to Rhodium regarding Cheapskate's prep: so according to two other bees, refluxing acetic acid and o-toluidine may not form NAOT.

References given to me in his question:
Post 108883 (Sky: "O-Toluidine or O-Tolidine HCL", Novel Discourse)
Post 108558 (dormouse: "Still playing with methaqualone  -Cheapskate", Novel Discourse)
../rhodium/chemistry /quaalude.cheapskate.html
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    Rhodium
(Chief Bee)
11-17-02 10:58
No 380531
      Acetic only  Bookmark   

J, Klosa (known from many articles written on Quaalude) published Patent US3197473 which is a method which does not use any other acetylating agent than acetic acid. The reaction is performed in polyphosphoric acid though. The full patent text can be found in Post 398805 (Aurelius: "US patent 3197473", General Discourse).

Send Cheapskate a PM about it, he stops by from time to time.
 
 
 
 
    Cheapskate
(Downer Dude)
12-06-02 10:37
No 386911
      But not every single time.  Bookmark   

I've done this exactly as MaDMax described above about 30 times.  I've had a few failures.

In the (maybe 5) times that failed the mother liquid just sat there and stared back at me and didn't form any crystals.  Never found out what went wrong.  In a few instances I tried some more reflux and more acid.  This worked once to create the crystals, but the other times....nada.

It worked perfectly the vast majority of the times.  I never, ever got the pretty white crystals that MaDMax did above.  They were always slightly pink.

Good job MaDMax!!
 
 
 
 
    Ritter
(Master Whacker)
12-06-02 14:22
No 386980
      your fix!  Bookmark   

Cheapskate,

If the rxn. fails to crystallize, adding a seed crystal from another batch will surely initiate crystallization of the desired product.  The amine was definitely acylated those times you experienced "failure", the product just failed to crystallize out.  Another way to isolate the N-Acetyl compound if crystallization fails is to simply evaporate off the excess acetic acid.  This will surely produce the desired solid product.
 
 
 
 
    Acetyl
(Stranger)
12-07-02 00:05
No 387087
      Water  Bookmark   

It turned out, as the bee in question PM'd me back, the problem was water in her acetic acid. She now refluxes for 5hrs and gets 60% yields. I sometimes wonder why she, herself, doesn't post that info in this thread.

Whatever. Take it easy guys, and a special thanks to madmax & his digital camera!

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