Sciencemadness Discussion Board

Need help with prep. of phthalic anhydride from naphthalene

prole - 5-9-2006 at 16:40

I am interested in preparing phthalic anhydride from naphthalene in order to prepare phthalimide, in an OTC fashion, of course. I have googled, and found plenty of info on going from the anhydride to phthalimide. Merck gives several refs, which I checked out. Faith, Keys, and Clark's Industrial Chemicals outlines a great procedure utilizing vanadium pentoxide catalyst and a maze of furnaces, cooling chambers, sublimation tanks, etc. This is beyond my humble basement/garage/back patio lab space, and I'm a little skittish ordering vanadium pentoxide, even though I would like some to try SO3 when my balls grow a little bigger. The one process Merck hinted at, using naphthalene with HgSO4 and CuSO4 in the presence of H2SO4 has thus far eluded me, but seems the most feasable. It was not in the above-mentioned volume, which I at first erroneously believed. Can anyone please offer a ref. or procedure using these chemicals? These reagents are within my grasp, indeed, they are within my lab. I know I can simply order phthalic anhydride, but why buy it when I can spend huge amounts of time and money trying to make it? Thank you in advance for your help, time, insults, and jabs.

I humbly remain,

-prole, the common clay chemist

leu - 5-9-2006 at 18:38

A laboratory scale apparatus for oxidizing napthalene is described in the Fundementals of Dye Chemistry which is available here if one looks around for it :P The process which is probably more suitable for the average laboratory is to chlorinate coarsely ground napthalene and then oxidize the napthalene tetrachloride with nitric acid:

Commercial nitric acid (sp gr 1.45 10 parts) is gradually added to napthalene tetrachloride (1 part) and the mixture heated until a clear solution is produced. This is then evaporated to dryness, and the residue distilled, the phthalic anhydride which passes over being reconverted into phthalic acid by dissolving it in dilute soda: the acid is then precipitated by adding a mineral acid, and the crystalline precipitate purified by recrystallization. Phthalic acid crystallizes in colorless prisms, and melts at 184 degrees, with the formation of the anhydride so that if the melting point is taken after solidification it will be 128 degrees, the melting point of phthalic anhydride

The oxidation with concentrated sulfuric acid and a small amount of mercury or mercuric sulfate is carried out at 220-300 degrees(GP 91202); which seems less easy than the procedure disclosed above. Another old procedure from nitronapthalene was disclosed in British Patent 145071.

:cool:



[Edited on 8-9-2006 by leu]

solo - 5-9-2006 at 19:01

I also had this from the Hive..........solo

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Chemistry Discourse Thread:


Posts 1 - 3 of 3 Subject: Phthalic Anhydride from Naphthalene




foxy2
(Distinctive Doe)
09-08-01 13:28
No 211336
Phthalic Anhydride from Naphthalene

This maybe of interest to anyone looking at Methaqualone.
Now if only they sold V2O5 at the grocery store!!!

Gibbs Phthalic Anhydride Process; Gibbs-Wohl Oxidation of
Naphthalene.


H. D. Gibbs and C. Conover, U.S. pat. 1,285,117 (1918)
A. Wohl, U.S. pat. 1,787,416-417 (1930)
R. N. Shreve, Chem. & Met. Eng. 52(5), 103, 117 (1943)
Kirk-Othmer, Encycl (New York, 1953)
Faith-Keyes-Clark, Industrial Chernicals, 2nd ed, p 610 (New York,
1957)
Kirk-Othmer, Encyclopedia of Chemical Technology 10, 585
L. F. Fieser and M. Fieser, Advanced Organic Chemistry, p 795 (New
York, 1961).

Do Your Part To Win The War


Rhodium
(Chief Bee)
09-08-01 13:47
No 211340
Re: Phthalic Anhydride from Naphthalene

I believe there is a method on my page for this transformation
using sulfuric acid as oxidant and mercury or mercury sulfate as
catalyst. If not, it is at least posted here.



PolytheneSam
(Master Searcher)
09-08-01 18:37
No 211399
Re: Phthalic Anhydride from Naphthalene

See US patent 729502 on an electrolytic process for making phthalic
acid from naphthalene.
http://www.geocities.com/dritte123/PSPF.html



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and some stuff which you may already know......




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pHarmacist
(Hive Addict)
03-03-03 16:21
No 413466
Two Methods for the Preparation of Phthalimide
(Rated as: excellent) Bookmark

pHarmacist's voice: A very neet way of preparing primary amines is by using Gabriel Synthesis. Most of you are familiar with Gabriel synthesis. For you that are not; it's basicly conversion of alkyl halides to corresponding primary amines by treatment with potassium phthalimide, followed by hydrolysis. In my opinion Gabriel Synthesis is a great route to phenetylamines. Below I introduce to you two methods for production of phthalimide - a reagent that is universaly used for Gabriel synthesis.

Mechanism for Gabriel synthesis:
[image]

Phthalimide:

Method 1. Place 100 g (0.675 mol) of phthalic anhydride and 105 mL of concentrated ammonia solution in a 1-litre round-bottomed flask fitted with a wide air condenser (10 mm in diameter). Heat on a sand bath, gradually at first until the mixture is in a state of quiet fusion and forms a homogeneous melt (the temperature reaches 300°C in about 1.5-2 hours; all the water is evaporatedduring the first hour). Shake the flask occasionally during the heating and push down any material whicj sublimes into the condenser with a glass rod. Pour the contents of the flask while still hot into a porcelain basin, allow to cool and grind to a fine powder in a mortar.

The phthalimide (95 g, 96%) is practically pure and melts at 233-234°C. It may be recrystallised from EtOH, but the solubility is only slight (about 5%).


Method 2. Intimately mix 99 g (0.67 mol) of pure phthalic anhydride and 20 g (0.33 mol) of urea, and placethe mixture in a 1-litre, long-necked, round-bottomed flask. Heat the flask in an oil bath at 130-135°C. When the contents have melte, effervescence commences and gradually increases in vigour; after 10-20 minutes, the mixture suddenly froths up to about three times the original volume (this is accompanied by rise in temperature to 150-160°C) and becomes almost solid. Remove the heat from beneath the bath and allow to cool. Add about 80 mL of water to disintegrate the solid in the flask, filter at the pump, wash with a little water and then dry at 100°C.

The yield of phthalimide, m.p. 233°C (i.e practically pure), is 86 g (87%). If desired, the phthalimide may be recrystallised from 1200 mL of industrial spirit; the first crop consists of 34 g of m.p 234°C, but further quantities may be recovered from mother-liquor.

Reference: VOGEL'S Textbook of Practical Organic Chemistry (5:th edition), page 1065-1066
Accept No Imitations, There Can Only Bee One; www.the-hive.ws



Aurelius
(Hive Addict)
03-03-03 16:38
No 413473
Anthranilic Acid Bookmark

Don't know if this has been posted here before, but it's relevant to the use of the Imide:

Take the phthalimide and stir it in 25% aqueous KOH for 1-2 hours at 0*C and then acidify with HCl to give Phthalamidic acid.

This acid reacted with NaOCl gives anthranilic acid.

OR

The Imide can be reacted with basic (NaOH) NaOCl in water at 80*C and then acidified to give Anthranilic acid.

The more anthranilic acid can recovered from solution after initial separation by the use of its Cu salt.

(p 660-661 Org. Chem. 3rd ed. Fieser&Fieser)





Rhodium
(Chief Bee)
03-03-03 16:47
No 413477
Copper anthranilate Bookmark

Aurelius: It has been detailed at my page in the Quaalude FAQ, but that tidbit about copper anthranilate was new to me. I suppose it is the Cu2+ salt?



Aurelius
(Hive Addict)
03-03-03 16:57
No 413487
copper salt Bookmark

I dont' know. the book didn't state which form was used. I would suppose Cupric as it is available more cheaply in the form of CuSO4



Aurelius
(Hive Addict)
03-03-03 18:49
No 413518
Another Anthranilic synthesis Bookmark

Anthranilic acid can be synthesized by the fusion of leucoindigo with KOH at lower temperatures.



Aurelius
(Hive Addict)
03-03-03 19:34
No 413531
Anthranilic acid by hypochlorite Bookmark

Post 108807 (dormouse: "Anthranilic acid from phthalimide using OTC sodiumhypochlorite solution -Methaco(s)m", Novel Discourse)

[Edited on 6-9-2006 by solo]

not_important - 6-9-2006 at 06:26

The V2O5 catalysed method in "Fundementals of Dye Chemistry" is similar to a lab level method I've seen elsewhere. The complexity of the industrial process comes about from the quanities used, the need to separate the reactants and products while consuming as little of other reagents as possible, and to reach maximum overall conversion with recycle of unreacted feedstock and so one. If you're not making multi-Kg amounts, batch isolation of the products is quite workable and much simplier than the industrial version.

You can get vanadium pentoxide from larger pottery supply sources; pick up some other glaze chemicals at the same time - K2CO3, B(OH)3, MnO2, Cu2O and CuO, CeO2, cobalt carbonate and oxide.

The trad method using sulfuric acid and mercury catalyst is in a number of older organic chem lab books, it has the advantage that you can be busted by both your countries drug control and evironmental agencies. The napthalene tetrachloride method might be similar, depending on local views on haloginated hydrocarbons. Pick the one that uses the easiest to obtain acid, sulferic or nitric.

That electrolytic oxidation is likely one using cerium salts, they tend to turn out not to work well for industrial applications but will work in the lab with a bit of tinkering. Again, pottery supply stores may stock CeO2, which can be converted to CeCl3 by refluxing with strong hydrochloric acid with occasional additions of alcohol to help reduce the CeO2.

unionised - 6-9-2006 at 11:15

I'd have a look at phthalate plasticisers --> phthalic acid --> phthalimide before I tried oxidising C10H8
I have certainly got phthalic acid this way from shredded cheap plastic ("vinyl" rather than latex or nitrile) gloves extracted with IPA then saponified with NaOH

BTW, in my experience CeO2 reacts very slowly with HCl, infuriatingly so.

Nicodem - 6-9-2006 at 11:58

I agree. Obtaining diethyl or dibutyl phthalate should not be difficult trough some specialized polymer resin supplier (and while ordering, buy also some styrene). (A google search for "plasticizers+phthalate+suppliers" gives 69000 hits!)

Oxidazing naphalene sounds incredibly unpracticale and messy, not to mention stupidly expensive for such a cheap compound like phthalic acid.

Depending on use, one should also ask himself why not using something else instead of phthalimide? If using it in a Gabriel synthesis is the goal, than there are other imides that perform just as well. For example, succinimide salts are even more nucleophilic*, though also ten times more basic. It can be just as easily prepared from succinic acid and ammonia, with the difference that buying succinic acid should not be as difficult as phthalic acid or phthalanhydride. One can even use saccharin in Gabriel synthesis of primary amines.

* J. Chem. Soc. Perkin Trans. II (1993) 1141- 1145.

prole - 6-9-2006 at 16:43

Thanks to all who've replied for your valuable insights and suggestions. I'm going to switch gears from utilizing mercury salts and high temps to either the vinyl glove approach or oxidising naphthalene tetrachloride with some nitric I've got stored away. I make my own soaps, so saponification is no mystery to me. Also, it's good to see some Hivespeak again. A bit more research, then it's off to the lab. Hurray! I'll post my results here when they become available.

-prole

[Edited on 1-5-2007 by Polverone]

leu - 7-9-2006 at 09:13

Some citations to a few articles discussing the synthesis of tetrachloronapthalene:

Turner, Wynne, J. Chem. Soc., 1941, 247.
Turner, Wynne, J. Chem. Soc., 1941, 253.
Turner, Wynne, J. Chem. Soc., 1941, 254.
Turner, Wynne, J. Chem. Soc., 1941, 256.
Piggott, Slinger, J. Chem. Soc., 1952, 259.

:D

not_important - 7-9-2006 at 21:31

Most any vinyl object that has some flex will be plasticised. Construction sites are good as the junk piles frequently have scrap plastic pipe, which usually is ABS, PVC, or CPVC, and perhaps sections of vinyl siding and trim. These will need to be chopped or ground up, their disadvantage vs being free.

leu - 19-9-2006 at 17:00

The synthesis of phthalic acid from napthalene via the oxidation of the tetrachloride from Chemical Abstracts 18 1120-2 (1924):

Attachment: ca18-1120+.zip (27kB)
This file has been downloaded 1031 times

Sauron - 23-12-2006 at 06:43

Phthalic anhydride is a very inexpensive compound. If your object is to make phthalimide then you will still have some work ahead of you. I made a kg or so a few years ago as a 5-finger exercise (still around here somewhere) using three different methods, the least subtle was conc ammonium hydroxide, but it worked. The others involved a solid mix of urea and.or ammonium carbonate IIRC. You'll need a mantle with a decent top end like a Glas Col STM and an air condenser, the stuff wants to sublimate and you may get some phthalimide snowflakes so do it in your hood. The stuff after all is a well known teratogen (remember Thalidomide?)

Then you need to convert to the K-salt if you are going to use this in the Gabriel.

Vogel gives good directions for a couple of these easy preps of phthalimide, I probably got the other from Org.Syn. online.

Suggestion: why not switch to o-Xylene as your starting material? That will oxidize with permanganate readily to phthalic acid or maybe the anhydride, in either case easily converted to phthalimide. o-Xylene is cheap and unrestricted. You needn't buy a very high grade of it. Lab grade ought to do. Maybe technical or practical grade if available. Mixed xylenes too wasteful as only the ortho will form what you want.



[Edited on 24-12-2006 by Sauron]

guy - 18-3-2007 at 17:28

Quote:
Originally posted by unionised
I'd have a look at phthalate plasticisers --> phthalic acid --> phthalimide before I tried oxidising C10H8
I have certainly got phthalic acid this way from shredded cheap plastic ("vinyl" rather than latex or nitrile) gloves extracted with IPA then saponified with NaOH

BTW, in my experience CeO2 reacts very slowly with HCl, infuriatingly so.


Can you describe this a little more? I just bought some vinyl gloves. Can denatured alcohol be used instead of IPA? How does the saponification procedure go?

Edit:

Ok so I added about 20 gloves into 200mL IPA. Heated this for a bit and stirred. The gloves became stiff and hard indicating that the plasticizing agent had been removed. So then I added a NaOH solution to it. There are 2 separate layers but the smell of the saponified alcohol started to be present. The smell was sweet but not pleasant and was actually quite nauseating. I wonder what it is; I think it is 2-ethylhexanol.

I haven't acidified it yet but I will tommorow.

[Edited on 3/18/2007 by guy]

unionised - 19-3-2007 at 11:22

Decant the mixed alcohols (the top layer) and acidify the lower aqueous layer. You should get a ppt of the acid you are after.
I think when I did it I used a solution of NaOH in wet ethanol so initially I just got one phase. When this reacted it gave a ppt of the Na salt of the desired acid but I can't be sure now (it was a while ago). I added water to get 2 phases and added acid to get phthalic acid and recystalised it.

I was going to use it (as the potassium H salt) as a pH standard but (1) I couldn't get the old pH meter I got from ebay to work and (2) I decided it would be easier to use cream of tartar.

guy - 19-3-2007 at 13:35

Ok I added HCl into the lower phase until it was acidic. Now I have a bunch of white needle crystals. Is this phthalic acid?

Edit:
Finished the box of gloves, 50 gloves. Got at least 15g. Still some more in the alcohol being precipitated out.

[Edited on 3/19/2007 by guy]

garage chemist - 19-3-2007 at 16:27

As fas as I know phthalates as plasticizers are banned in some countries or their use is at least regulated, because of various long-term health effects.

And, please tell me you arent serious with latex gloves as a source of phthalic acid. If this is a research project as to which gloves contain the most phthalates then fine, but if this is meant as an actual source for it then its the most ridiculous attempt at OTC chemicals that I've ever seen.
Phthalic anhydride can be obtained by absolutely everyone, there will be no objections if you order it in the pharmacy. There are countless legit uses of it for the average science fair project (e.g. preparation of fluorescein).

I have also prepared phthalimide from phthalic anhydride, using urea melt. This worked nicely and the product was reasonably pure as indicated by the melting point.
Athranilic acid from this did not work well however, I got dark brown gunk with too low a melting point and which couldnt be recrystallized. I think it could be purified by forming the methyl ester, steamdistilling this and then hydrolysing it.

But this is no longer of importance, since I heard that methyl anthranilate can be bought unrestricted contrary to the acid and I got me some.

unionised - 21-3-2007 at 11:04

"And, please tell me you arent serious with latex gloves as a source of phthalic acid. If this is a research project as to which gloves contain the most phthalates then fine, but if this is meant as an actual source for it then its the most ridiculous attempt at OTC chemicals that I've ever seen.
"
OK, I'm not serious about latex gloves because I can tell PVC from rubber. The gloves are about 50% weight phthalate; if it's the dibutyl ester then that's about 25% phthalic acid. I have seen much worse yields than that.
I would also like to point out that this method is ridiculous in the rather odd sense that
1 it works
and
2 A couple of us have done it.
BTW, I simply don't want to be seen as "that weird bloke who orders strange chemicals" in the local pharmacy or any other pharmacy.

guy - 21-3-2007 at 11:14

Quote:
Originally posted by unionised
"And, please tell me you arent serious with latex gloves as a source of phthalic acid. If this is a research project as to which gloves contain the most phthalates then fine, but if this is meant as an actual source for it then its the most ridiculous attempt at OTC chemicals that I've ever seen.
"
OK, I'm not serious about latex gloves because I can tell PVC from rubber. The gloves are about 50% weight phthalate; if it's the dibutyl ester then that's about 25% phthalic acid. I have seen much worse yields than that.
I would also like to point out that this method is ridiculous in the rather odd sense that
1 it works
and
2 A couple of us have done it.
BTW, I simply don't want to be seen as "that weird bloke who orders strange chemicals" in the local pharmacy or any other pharmacy.


So 16g is pretty bad yield? Can you tell me how to improve the yields? This is my procedure:

50 gloves where cut up and dissolved in ~200mL of 99%IPA. This was heated to the boiling point and stirred for about 5 minutes until the plastic became stiff.

Then I removed the glove pieces. I added a NaOH solution (in water) and shook it. I didnt't measure the amount of NaOH because I didn't know how much ester I had. Then I separated the layer and added HCl and waited until white needly crystals precipitated.

Maybe for better yields I should use the right amount of NaOH and dissolve that in EtOH to get a more homogenous solution with the IPA.


It seems the ester used in the gloves is <a href="http://en.wikipedia.org/wiki/Di-2-ethyl_hexyl_phthalate">this</a>



[Edited on 3/21/2007 by guy]

unionised - 22-3-2007 at 11:53

How much does a glove weigh? Also, if it's the dioctyl ester the yield will be worse.
I'd try re exttracting the leftover IPA/isooctanol/whatever mixture with NaOH soln and seing if any more ester is there to hydrolyse.

jon - 22-3-2007 at 13:05

is there a way to get the pthalimide from the ester by reaction with ammonia at high temp and pressure?

guy - 22-3-2007 at 19:35

Quote:
Originally posted by jon
is there a way to get the pthalimide from the ester by reaction with ammonia at high temp and pressure?


Why would you want to do that though? Its seems harder. But yea, you probably can.

UnintentionalChaos - 22-3-2007 at 21:14

Another thought is that the fluid in glow sticks is the same phthalic acid ester. Im not sure if using them instead would be more cost efficient and you avoid wasting your IPA. You would have to deal with the dye and phenol oxalate ester as well as what sounds like a significant portion of sodium salicylate. Since the salicylate salt is very water soluble and the phthalic ester is not, a series of water extractions could also furnish the salicylate salt for future experiments (plus the little ampoules of 35% H2O2 are probably good for test tube experiments). After hydrolyzing the hydrophobic remains with alcoholic NaOH and then acidfying, washing the ppt should give you fairly clean phthalic acid. Anyone have glow sticks lying around?

jon - 23-3-2007 at 16:55

little off topic but alkali hydrolysis of leuko indigo seems to be the easiest route to anthranilic acid, it tends to easily oxidize back to indigo.

UnintentionalChaos - 24-3-2007 at 10:00

Maybe I'm just really tired, but I don't follow what you mean by alkali hydrolysis of the indoxyl. Could permanganate crack the pyrrole ring in the right place (Seeing as how it breaks napthalene)? You could sulfonate the indigo first so it is at least soluble (still not very soluble 1g/100ml). I am not very experienced in organics (next semester) so I could be making no sense right now and wouldn't know it. :D

jon - 24-3-2007 at 15:09

lueko indigo looks like two indole rings fused together with a hydroxy group on each ring, you can get a structure of it in wikipedia, if you look close you'll see what a handy precusor it could be.

UnintentionalChaos - 24-3-2007 at 16:08

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]

guy - 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.

jon - 25-3-2007 at 21:38

yes anthranilic acid is watched because it is precursor to acetylanthranilic acid which is the precusor to methaqualone.

UnintentionalChaos - 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]

guy - 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.

not_important - 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]

UnintentionalChaos - 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.

tupence_hapeny - 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]

tupence_hapeny - 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?

Nicodem - 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.

tupence_hapeny - 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

neilson80 - 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

Magpie - 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.)

Magpie - 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

UnintentionalChaos - 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]

Magpie - 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%. ;)

Phthalic acid/ phthalic anhydride via Aqua Regina

Alchemist - 7-7-2008 at 07:53

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]

Nicodem - 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]

Phthalic acid/ phthalic anhydride via Aqua Regina

Alchemist - 10-7-2008 at 15:13

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.....

un0me2 - 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 729 times

Attachment: Weissman.Schoenheimer.The.Relative.Stability.of.Lysine.in.Rats.Studied.with.Deuterium.and.Heavy.Nitrogen.pdf (843kB)
This file has been downloaded 797 times