Sciencemadness Discussion Board

Hydrolysis of amino-benzoate esters in Benzyl Benzoate

samm - 28-7-2017 at 13:28

I have some Methyl Anthranilate that I believe I have a reasonable method for hydrolysis back to the acid using first 100ml 3N NaOH pr 30ml and then strong vinegar, but this product states "%50 in Benzyl Benzoate", so I figured I'd ask if anyone has suggestions for separating the (unwanted) benzoic acid away from the anthranilic acid.

So after the 100ml 3N/~30ml/100C hydrolysis, I've been adding about 1ml 36% hcl per 100ml of water, and instantly out crashes some clumpy white crystals that don't look anything like the pinkish AA crystals that I get next after filtering and then adding about 2x volume of vinegar and chilling. The first batch of crystals are very fine, clumpy like cheese and typically pretty white, they also form basically instantly. The second batch is again, pinkish to sometimes a dirty red depending on the mother-liquor concentrations.

So my guess is the second batch is mostly AA with some benzoic acid to boot. Can anyone suggest maybe a solvent or re-x idea that could further clean this AA? Any and all suggestions welcome. I have used just plain water to re-x AA, but I wonder if there is anything superior in washing out Benzoic Acid. FWIW I have read the other threads on this board that cover hydrolysis of MA, but I haven't seen any real relevant discussion about purification.

Maybe another wash or a re-x in hot AcOH?

[Edited on 28-7-2017 by samm]

Metacelsus - 28-7-2017 at 14:39

You might be able to separate the mixture beforehand using vacuum distillation. Under atmospheric pressure, methyl anthranilate boils at 256 °C whereas benzyl benzoate boils at 323 °C. I expect the difference in boiling points would largely remain under lower pressure.

JJay - 28-7-2017 at 15:32

You might be able to precipitate dissolved anthranilic acid out of chloroform with hydrogen chloride. Anthranilic acid is a controlled methaqualone precursor, but somehow I doubt that you're trying to whip up a batch of quaaludes, and it has a lot of legitimate uses. I wish I had some for making making n-phenylanthranilic acid, which I can't seem to find anywhere.

samm - 28-7-2017 at 16:03

Quote:

You might be able to precipitate dissolved anthranilic acid out of chloroform with hydrogen chloride.


Ok, I thought it was completely soluble in chcl3, do you know if it has the same properties in DCM? (easier for me to access)

thx

[Edited on 29-7-2017 by samm]

JJay - 28-7-2017 at 16:16

What are you doing with anthranilic acid?

samm - 28-7-2017 at 17:56

Why does it matter?

Do you ask people why they want ethanol?























(I like to play with it when it's acetylated)

[Edited on 29-7-2017 by samm]

XeonTheMGPony - 28-7-2017 at 18:06

We get a lot of idiot meth cooks and skiddies as I call them wanting to be spoon fed info to "cook" with. I don't waste time with that garbage so no idea if the chemicals can be used for such but that is the reason he may be asking.

and around here yes, one would ask why they wanted ethanol, as it could help us to further help the person by offering alternative options or assisting in procedural methodology and so much more.

samm - 28-7-2017 at 18:12

I don't cook meth, can't stand the shit -- though if I did I'm not sure how it's anyone's business here? Me I'm a big fan of the first amendment, IDK about ya'll.

Not looking for spoon-feeding, promise I've done a shit-ton of research with minimal hand-holding here. Just looking for some ideas, which I got, so thanks.




XeonTheMGPony - 28-7-2017 at 18:21

Why it is our business is those losers wreck our over all image, every time some one finds I do chemistry they reference breaking bad causing me to see the dentist from all the tooth grinding!

Any ways, we will do every thing we can to help with legitimate educational chemistry and technical questions, but drug cooks find them selfs in the garbage bin promptly here and for that we all can be proud!

Just a further explanation, glad you are finding the help you need

FYI the first amendment only applies to government ;) Not private shops or boards.

samm - 28-7-2017 at 18:34

Fair point.

FWIW I don't think this board has anywhere near the image of that of a drug-cookery site. On the contrary most often it seems to get called out by someone at some point. Fine with me.

cheers

Metacelsus - 29-7-2017 at 04:40

Copper(II) forms an insoluble complex with anthranilic acid. You could try precipitating copper anthranilate. However, recovering free anthranilic acid from the complex is not easy (gassing with hydrogen sulfide is the only method I've heard of, and I would advise against that for safety reasons).

I would also advise against making methaqualone. Instead, you use anthranilic acid for interesting experiments with benzyne, by diazotizing the anthranilic acid and then heating to eliminate nitrogen and carbon dioxide.

samm - 29-7-2017 at 14:20

Today I decided to re-x these two products to see how they behave and how well they clean up. I used plain DH2O for the benzoic acid, and DH20 to dissolve the anthranilic acid, and then more "cleaning vinegar" to re-precipitate it. As a ghetto control, I also added some vinegar to a portion of the benzoic acid in DH2O to see if it would also precipitate out at this PH.

The Anthranilic Acid behaved as usual, and as it did when I did this with smaller amounts of MA that wasn't diluted with Benzyl Benzoate. Basically it will dissolve in hot neutral/alkaline H2O fairly well, but slowly starts crystallizing out into small light pink/red needles at rt. The (suspected) Benzoic Acid will dissolve in neutral, hot H2O; but very rapidly re-precipitates as the water cools back to RT into fine, clumpy, white crystals. The AA doesn't do this, it wants to be much colder, precipitates slower and yields much better when the PH ~3.5, and also when allowed to chill overnight. Interestingly, the Benzoic Acid seems even more soluble in cold vinegar than in rt, neutral DH2O, exactly where the AA isn't.

I haven't run a MP yet, tonight or tomorrow. So far I'm pretty impressed at how well separation is working at neutral and then ~3.5.

I remember reading about another poster who was having some trouble hydrolysing MA>>AA, so maybe this will be useful to someone else.

[Edited on 29-7-2017 by samm]

unionised - 30-7-2017 at 08:59

I'm fairly sure that benzoic acid is much more soluble in low polarity solvents like toluene than anthranilic acid because the amino acid exists -at least in part- as a zwitterion.

Tellurium - 31-7-2017 at 23:20

Quote: Originally posted by Metacelsus  
Copper(II) forms an insoluble complex with anthranilic acid. You could try precipitating copper anthranilate.

Copper benzoate is also nearly insoluble, so i think it also would be a problem, since both, the copper anthranilate and the benzoate would fall out of solution:(