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Author: Subject: Need help with prep. of phthalic anhydride from naphthalene
guy
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[*] posted on 25-3-2007 at 13:41


Quote:
Originally posted by UnintentionalChaos
Ah, found it on the German page. The english has either leucoindigo or indigo white meaning the same thing. It's an ethylamine short of tryptamine, if that is what you mean, though I am not interested in that area. I assume that anthranilic acid can be used to make tryptamines and that is why it is watched, but my point was, if you wanted anthranilic acid from indigo for the heck of getting anthranilic acid, could permanganate get you there?

guy- I also did an extraction (though have not saponified it yet) of 12 gloves which lost about 30% of their mass after extraction. This seems like too even a number to be a mistake. I used 12 "Mr. Clean" vinyl gloves , shredded and washed them to remove the powder, and left overnight in denatured alcohol (roughly equal parts methanol and ethanol and 1-4% of methyl isobutyl ketone). I should get roughly 6.9g phthalic acid if yield is perfect and if your gloves were identical, you would have recovered almost 28.8g. Did you manage to improve your yields any?


[Edited on 3-24-07 by UnintentionalChaos]


I haven't re-tried it yet. I think I will soon. I'll weigh them this time and I'll saponify it using alcoholic NaOH so there is better mixing and the salt also separates out.




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[*] posted on 25-3-2007 at 21:38


yes anthranilic acid is watched because it is precursor to acetylanthranilic acid which is the precusor to methaqualone.
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UnintentionalChaos
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[*] posted on 30-3-2007 at 16:26


This is a bit weird, but I may have a side reaction that I can't explain occuring with the alcoholic solution of plasticizer. I am fairly sure that I extracted bis-(2-ethylhexyl)phthalate into a mixture of ethanol and methanol (with a bit of methyl isobutyl ketone). This sat around for a few days and definetly spent some time in the sun, probably getting fairly warm. Now it has this bizarre odor to it that I can't quite explain. The best description of it that I can give is acrid cheap artificial watermelon scent gone bad. The scent is quite sharp and "acidic." Is this possibly 2-ethyl hexanol, and if not what could it possibly be?

The sharpness of the scent leads me to believe that it may be an acid, but out of what is in the mix, I have no idea what would be oxidizing the alcohols.

[Edited on 3-30-07 by UnintentionalChaos]




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guy
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[*] posted on 30-3-2007 at 16:51


Quote:
Originally posted by UnintentionalChaos
This is a bit weird, but I may have a side reaction that I can't explain occuring with the alcoholic solution of plasticizer. I am fairly sure that I extracted bis-(2-ethylhexyl)phthalate into a mixture of ethanol and methanol (with a bit of methyl isobutyl ketone). This sat around for a few days and definetly spent some time in the sun, probably getting fairly warm. Now it has this bizarre odor to it that I can't quite explain. The best description of it that I can give is acrid cheap artificial watermelon scent gone bad. The scent is quite sharp and "acidic." Is this possibly 2-ethyl hexanol, and if not what could it possibly be?

The sharpness of the scent leads me to believe that it may be an acid, but out of what is in the mix, I have no idea what would be oxidizing the alcohols.

[Edited on 3-30-07 by UnintentionalChaos]


Yeah I got that too. I think its partly the acid because when I heated the acid, it sublimed and it smelled like acrid. But the sweet nauseating smell is the alcohol.
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not_important
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[*] posted on 30-3-2007 at 16:52


2-ethyl-1-hexanol

odor type : citrus
odor strength : Medium
odor description : At 100.00 %. citrus fresh floral oily sweet
substantivity : 16 Hour(s)

http://www.thegoodscentscompany.com/data/rw1015291.html


And it doesn't seem likely that the phthalate should have hydrolysed without a catalyst.

Other desctptions of the oder include "sweet-pungent smell" and "rose-like" Go figure. It could be you have other esters than 2-Eth-hex


[Edited on 31-3-2007 by not_important]
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UnintentionalChaos
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[*] posted on 30-3-2007 at 17:47


No alkali got anywhere near that bottle though...photo-catalyzed hydrolysis (alcohol was not quite dry)? The odor was mild before. Now that I have added NaOH, the smell is considerably more intense. Good to know something hasn't gone awry again, though.



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tupence_hapeny
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[*] posted on 19-5-2007 at 01:46


I just found this article:

M. Gupta et al. 'ZnO for Benzylic Oxidations' Tetrahedron Letters 46 (2006) 4597

If someone can upload the article others will be able to read it, it provides that using ZnO (in DBM or DMF (would other solvents work?)) and under MW irradiation for 7.5 min, naphthalene can be converted to phthalic acid in 78% yield.

This represents a serious benefit to those seeking to make this substance, and it is actually easier to make than extract the sucker from latex - go figure...

tup

Thanks to Solo who provided the uploaded link to this article:

http://www.4shared.com/file/16243590/83746656/ZnO_for_Benzyl...


[Edited on 19-5-2007 by tupence_hapeny]




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[*] posted on 25-5-2007 at 05:00


Anyone got any ideas for solvents for this? Other than the next to impossible for me to get DMF?

Alternatively, could I just use shitloads of naphthalene (melts @ ~80C - may be slightly more in MW)?

I am thinking that this would be useful, simply distill of the naphthalene (@~218C) with the effect of causing the decomposition of the phthalic acid into phthalic anhydride (@~210) - which would be great if no other solvent needed to be dealt with.

tup

PS Nicodem, is this another example of my making reactions way too complex for 'amateur' chemists?




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[*] posted on 25-5-2007 at 08:19


Quote:
Originally posted by tupence_hapeny
PS Nicodem, is this another example of my making reactions way too complex for 'amateur' chemists?

Not only that. It is also another example of you promoting articles smelling of bullshit. But that is understandable giving your total lack of any insight in the reaction mechanisms.
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[*] posted on 25-5-2007 at 11:18


Fuck me,

I thought I had problems.

Ok, I have researched and referenced an article from a 'refereed journal' as required by yourself and others... I have taken onboard your criticism regarding the use of additional solvents when they are not required - taking also your suggestion that I should instead simply utilise an excess of reactant as solvent. I have also made a serious attempt to simplify the reaction as suggested, in fact I do not believe that I could have gone further in this regard...

Now, having done all that is necessary (or has been previously stated to be a pre-requisite in order to seek enlightenment) - instead of gaining that enlightenment for which I ask - I am merely to be informed that I am unenlightened?

I am aware of that fact, in fact, I have admitted to the truth of that statement. Now, if possible, would it bother you so much to provide some information as to whether or not the reaction as suggested will (1) blow up, killing myself and housemates; (2) give off noxious fumes to the same effect as (1); (3) fail to work as advertised (and if so, I would appreciate information as to why, how, etc); and/or (4) Simply fail to do anything at all.

I am sorry if I, as one of the uninformed, have transgressed by seeking advice and suggestions from yourself as one of the enlightened few, however, I believe that this board exists for precisely such a purpose, does it not?

PS Apologies, as it has been pointed out by myself earlier I am pathologically incapable of feeling remorse, it should be blindingly fucking obvious that any apology from me is somewhat insincere, once again - apologies.:D




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[*] posted on 23-6-2007 at 16:35


Hey guys, I've just extracted several ounces of phthalic acid from a vinyl shower curtain, using methanol to extract the dehp ester. I saponified this with KOH solution, and then acidified the lower layer with HCL. Phthalic acid started to precipitate out immediately (In very large amounts). I find that clear vinyl shower curtains, are on a weight basis, far more economical to use compared to gloves. If the shower curtain is clear, noncoloured, and transparent, it will not contain any tin stabilizers. With this method, I can extract pthalic acid and on a KG level for only a few dollars!:D
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[*] posted on 23-6-2007 at 18:56


Nice work. ;) Can you determine a melting point to confirm identity of your crystals?

(I've been wanting some phthalic acid myself.)




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[*] posted on 7-11-2007 at 14:39


Here's my contribution to phthalic acid by extraction of plasticizer from plastic.

I extracted 10 cut up Playtex vinyl gloves with about 250 mL of 99% IPA. I brought the IPA up to near boiling and stirred for about 1/2 hour. This was then filtered to remove all glove fragments.

Assuming that up to 50% of the weight of the gloves was dioctyl phthalate I calculated the amount of NaOH needed and then doubled it. (Based on what the soap makers do I should have used only a stoichiometric amount - I later learned). The NaOH was dissolved in 100mL of water and then added to the IPA. Further stirring resulted in the formation of two phases as the saponification took place. I then decanted off the upper IPA layer, saving it for later recovery of the IPA and 2-ethyl hexan-1-ol.

To the lower water layer I added dilute HCl to a pH of 3. Fine white needles, with a few small flakes, of phthalic acid appeared. I caught these on a Buchner funnel - shown in the jar below. I saved the mother liquor and harvested a second crop of crystals this time in the form of huge flakes, shown in the weigh pan. I carefully washed some of the fine crystals and determined a sealed tube mp = 189-190C (literature = 191C).

By distillation I recovered the IPA and subsequently the 2-ethyl hexan-1-ol. The later came over at 180C (literature = 183C).

Assuming that the gloves were 50% DOP my yield based on phthalic acid recovered = 33%.

My apologies to garage chemist, but I must say that my sympathies lie with unionised on this. I can buy phthalic acid and phthalic anhyride inconspicuously but they are by no means cheap when freight and hazmat fees :mad: are added. Additionaly, this is a fun experiment if you have not done it before. It is like extracting a natural product, and it progresses quickly.

phthalic acid.jpg - 62kB




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UnintentionalChaos
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[*] posted on 7-11-2007 at 19:04


I weighed the glove shreds before and after extraction. I got 30% weight plasticizer, so i imagine that that will be somewhat universal for gloves.

Your yield probably doesn't suck nearly as much as you think it does.

[Edited on 11-7-07 by UnintentionalChaos]




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[*] posted on 7-11-2007 at 21:35


Quote:

Your yield probably doesn't suck nearly as much as you think it does.


I didn't use many gloves. But mostly I think I just used too much water. And, as you say, the initial loading may well have been closer to 30% than 50%. ;)




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[*] posted on 7-7-2008 at 07:53
Phthalic acid/ phthalic anhydride via Aqua Regina


Hello all,

I have an idea and thats all it is at this point. Will Aqua Regina oxidize Naphthalene to Phthalic Acid or the anhydride, and if NOT, what? How much KNO3/HCL should I use and how long should I heat it? What temperature should I keep it at? Any help would really be appreciated. Maybe I'll just try a number of small scale experiments and see what I get! Also maybe someone else would like to try this along with me and also report back with there results. I'll do the same and report back in a day or so!

Thanks, the Alchemist.....

<sub>Edit by Nicodem: This post has been merged with the thread of the same topic. Please use existing threads for questions on the same topic.</sub>

[Edited on 7/7/2008 by Nicodem]

[Edited on 8-7-2008 by Alchemist]
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[*] posted on 7-7-2008 at 09:18


What reference for naphthalene oxidation with HNO3/HCl do you have? (Vanadium oxides are usually used as catalysts for the oxidation of naphthalene phthalic anhydride and the oxidant can be O2, H2O2 and similar). Leu posted a procedure in this thread that uses nitric acid but with 1,2,3,4-tetrachloronaphthalene as substrate. But it mentions no aqua regia and I'm not even sure it would work on naphthalene as well. Anyway, if this is your own idea and just want to try out, you will need at least a stoichiometric amount of HNO3 (and the appropriate amount of HCl), but having 30-100% excess oxidant will probably not hurt (and might be necessary). A stoichiometric amount would mean 18 equivalents of HNO3 if HNO3/HCl/H2O of high concentration is used (HNO3=>NO2), or 6 equivalents if a more diluted solution is used (HNO3=>NO2). You will need a terribly good stirrer to run such an oxidation, since there is not much you could use as cosolvent (except perhaps acetic acid).

[Edited on 7/7/2008 by Nicodem]




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[*] posted on 10-7-2008 at 15:13
Phthalic acid/ phthalic anhydride via Aqua Regina


Hello all,

Here is a small update; read "LAURENT'S ORGANIC CLASSIFICATION"(it's posted here) Pg509 and look for footnote 128.


Regards, the Alchemist.....
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[*] posted on 12-7-2010 at 04:42


Here is an old article using labeled N/D amino acids, which are made from the thermal dehydration of ammonium hydrogen ortho-phthalate, then forming the potassium phthalimide (pp.9-10 of the attached article).

They then form the relevant amino acids from the a-ketoacids/etc. and recover the same with acid hydrolysis from the phthalimide in good yield.

Something to think about, eh?

No anhydride, no hydrazine, no worries...

They use the same procedure with CuO (IIRC) in the second paper too.

Attachment: Braun.etal.Benzopolymethylene.Compounds.X.Oxidative.Degradation.of.Tetralin.and.Substituted.Tetralins.to.Phthalonic.Acid (166kB)
This file has been downloaded 669 times

Attachment: Weissman.Schoenheimer.The.Relative.Stability.of.Lysine.in.Rats.Studied.with.Deuterium.and.Heavy.Nitrogen.pdf (843kB)
This file has been downloaded 730 times

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