Author Topic: N-acetylanthranilic acid  (Read 5427 times)

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kazoo

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N-acetylanthranilic acid
« on: April 19, 2000, 05:30:00 PM »
Oxidation of N-acetyl-o-toluidine with potassium permanganate and magnesium sulfate works very well in a very well stirred conical flask.  A large, inverted glass funnel attached to the aspirator hose makes a little mini-hood to whisk away unwanted pink steam from the reaction cooking away at a steady clip.  After parting with and washing the manganese dioxide sludge sulfuric acid was titrated into the remaining, chilled reaction mixture to induce copious crystalization.  Yield. 17.54 g from 20.00 g of starting material.  This cleaned up very nicely, once with the acid/base method (easy on the base) and once with the alcohol.  The alcohol is cleaner, by far.

A pseudo-run failed in an ugly, burnt oil that would not crystalize after a week or so of trying.

After going to the Water Buffalo Lodge with Fred they got the idea to consider turning their yield into something else.  It seems that they should concern themselves with the downstream reaction conditions.  Had they done it a second time, they might have raised the temperature steadily in an oil bath from RT to 180 and then kept it in the 175 to 195 range for 6 hours.  The material could have darkened slightly and might have even climbed the walls of the flask in long "legs."  The cooled material would not have turned viscous  and would not ppt crystals when disolved in 2x acetone and the same amount of conc HCl, (listed at 35 to 36 percent).

This begs the question...where for art thou crystals???

One other thing.  Barney might be working off of an old supply of o-toluidine.  It is cabernet colored and smells slightly of diesel fuel.  It seems that it would work well in step one and two.  Would it be a problem?

peace

kazoo



Cheapskate

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Re: N-acetylanthranilic acid
« Reply #1 on: April 20, 2000, 08:48:00 PM »
This has been seen, but only when too much o-toluidine has been used.  This may be your problem, but I don't think so.  If you haven't gotten completely disgusted and thrown the stuff away, gently warm it and evaporate the HCl and acetone away leaving a crusty mess behind. Now using just enough clean dry (magnesium sulfate helps here) acetone dissolve the mess.  If there are solids that won't dissolve filter them out they may be what you're looking for.  Now try the crystalization again with the lower amount of acetone and HCl.  If this doesn't work, evap to a mess again and dump in water with NaOH at around ph11 and see if it will solidify into a purple grainy mess of another kind.  If it does save this mess (filtering and discarding the basic water) and do the acetone, HCl route again.

If this doesn't work dump the shit down the drain and start over.


kazoo

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Re: N-acetylanthranilic acid
« Reply #2 on: April 21, 2000, 11:04:00 AM »
Thank you Mr. C. for your thoughtful reply.  Too much o-toluidine, eh?  Barney just loves to evaporate to dryness.



kazoo

  • Guest
Re: N-acetylanthranilic acid
« Reply #3 on: April 25, 2000, 06:08:00 PM »
Betty told me that Barney spent most of yesterday in his humble laboratory trying very unsuccessfully to raise a crop of crystals from a slightly viscous, dark purple solution of acetone and conc. HCl.  First he evap'ed to a deep purple sticky stuff which was rinsed with cold acetone.  Then he added acetone and heated to boiling.  Some of the residue, and yes he was ready to call it just that, refused to dissolve so he added some methanol and it all suspended into a fine slurry (like it would all go through the filter)  A few ml's DH2O did nothing.  He again evap'ed to dryness and added 0.025 M NaOH to a much less purple, actually close to black, residue.  The material suspended/dissolved and is now chillin' as we speak with a deep purple cast.  It smells sorta like burnt gearbox oil, which is possibly all it is.

Barney has a good attitude.  He is ready to scrap this process and move on to other past times.

Thank you for your informative replies.


Cheapskate

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Re: N-acetylanthranilic acid
« Reply #4 on: April 25, 2000, 06:57:00 PM »
Sorry you have to deal with this crap, but don't give up too soon if you have the time to fiddle with it.  The idea is, the methaqualone.hcl won't dissolve in acetone, while the crap will.  Methaqualone the base will dissolve in acetone.  So the crystalization relys on the mtq dissolving into the acetone and the HCl hunting it down and binding to form the .HCl and dropping out of solution.  Then just filter it and clean it up.

Well, you tried that and it didn't work so drying everything out and trying again is a good idea --- you tried that and it didn't work.  The methanol is a baaaad idea.  Methanol will dissolve everything and keep it.  One would have to evap down to dry AGAIN and go at it with acetone.  Don't rinse with acetone!  Like I said, acetone will dissolve the mtq base and take it away. 

May I suggest you do the acetone trick one more time?  Dry the crap as dry as you can get it, it'll probably still be a sticky purple mess.  Now add acetone and heat to dissolve as much of it as you can and filter, saving the solids.  Set the acetoneandcrap aside for other tests.  Now take a look at the filtrate, is it a slightly purple microcrystaline solid?  If so, evaporate the acetone and take a look at the dry solid.  Is it sticky (it shouldn't be) still tiny, tiny crystals?  If so, you may well have succeeded!!  Take the solid and do the acetone thing again.  Try to dissolve the solid in acetone, if it doesn't, filter and keep it.  If it's what you're seeking it will get cleaner and less purple.  Now go to the end of the write up I did and do the acidic water clean up and have fun.

Sometimes recognizing success is hard to do, so test it and see what happens.

It may be that the slurry you saw before adding the methanol was what you wanted.  Remember that mtq.hcl won't dissolve in acetone.  It could be that the slurry is exactly what you're going after. 


Rhodium

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Triboluminescent N-Acetylanthranilic Acid
« Reply #5 on: October 05, 2004, 05:18:00 PM »

lutesium

  • Guest
The anththranillic acid N-acetyl ester glows...
« Reply #6 on: October 06, 2004, 06:09:00 AM »
The anththranillic acid N-acetyl ester glows in the dark when totally dry, pure and hit with a glass rod on a glass plate.
Just an interesting lovely info..

For the reaction:

The reaction of an. acid. ester with an amine is what your doin. This is a general way of creating an oxazilodine (or I dont know the exact speling) ring and applied in many laboratories.

I can say that I also applied the reactions with amines and acids and what I observed is that you better do it on a small scale ( the rxn releases water and the excess amine steam distills before it can react!) and evaporate the water well in a open reaction flask like a beaker till it doesnt seem to be giving off any more vapor. The mix must solidify when cold (at about 80c)- test by dripping a glass rod in the rxn. Take the rod out , cool. Ýf a solid wax is there the rxn can be considered complete.
  This wax immediately turns to a big crystal mass upon addition of little acid.

lutesium

  • Guest
And just to add: I wouldnt ingest hommade...
« Reply #7 on: October 06, 2004, 06:18:00 AM »
And just to add:
I wouldnt ingest hommade methaaqualone because of the big possiblity of contamination. Even if it looks like a crystalline solid it may (and will) contain the HCl salt of o-Toluidine if not cleaned properly. Toluidines are highly carcinogenic and dangerous.

Dont ingest every white powder that you create. Pharmaceuticals created from toxic reactants or intermediates should be cleaned with a good strategy an tested for purity before ingestion.

Be careful