Sciencemadness Discussion Board - Oxidation of naphthalene with nitric acid

Oxidation of naphthalene with nitric acid

learningChem - 18-10-2012 at 18:43

Quote:

when naphthalene is boiled with diluted nitric acid, it is oxidized to phtalic acid and oxalic acid

(no further information)

pg. 429 - manual of the chemistry of C compounds - C. Shorlemmer -

http://archive.org/details/amanualchemistr02schogoog

-------------

That's all the information I could find. Any hints as to where I can find some kind of guideline for the reaction? Any hints as to how diluted is 'diluted' nitric acid?

I refluxed ~0.7g of naphtalene in 12ml 15% nitric acid for ~30 minutes and I got something that looks like a chunk of nitronaphthalene...Also, looks like the mixture doesn't boil easily. It tends to 'flash boil'...

learningChem - 20-10-2012 at 11:31

So....I see that this topic has 70 views and not a single reply?

Was my question too dumb?

Vargouille - 20-10-2012 at 12:01

More likely more because it couldn't be found in OrgSyn or through the ChemSynthesis Database. It might be in Vogel, but Adobe Reader keeps crashing on me, so I'm not sure.

kristofvagyok - 20-10-2012 at 12:08

I have no personal experience in destructive oxidizing aromatics. The only thing what I did and was similar that I have tried to make some mellitic acid from graphite with ccHNO3 and some heat... I've got a big black nothing.

Have you tried to analyse your product? Calcium oxalate is a not so well soluble thing... And nitronaphthalene has a sharp melting point, it is also soluble in organics solvents, while the carboxylic acids are not...

learningChem - 20-10-2012 at 12:12

I tried vogel, gatterman and a "watt's dictionary of chemistry" and found nothing. However, I was expecting people here to have some kind of general knowledge about the subject?

learningChem - 20-10-2012 at 12:20

Thanks kristofvagyok

My analysis was just visual analysis. Most of the naphthalene has turned into a yellow compound which looks exactly like the stuff I got in the past by nitrating naphthalene with nitric/sulfuric acid. There's also stuff that looks like unreacted naphthalene floating around.

I should try precipitating the oxalic acid (assuming there's any) with, say, calcium carbonate?

kristofvagyok - 20-10-2012 at 12:24

Quote: Originally posted by learningChem

I should try precipitating the oxalic acid (assuming there's any) with, say, calcium carbonate?

Yes, that should work(:

Vargouille - 20-10-2012 at 13:27

Quote: Originally posted by learningChem

I should try precipitating the oxalic acid (assuming there's any) with, say, calcium carbonate?

I should think an aqueous solution of calcium chloride, or any soluble calcium salt would be better than calcium carbonate. Oxalic acid is soluble in water, while phthalic acid is much less so, so you can isolate it that way. Granted, calcium carbonate would react with oxalic acid to form insoluble calcium oxalate, but a precipitate like calcium oxalate is easier to recognize, in my mind, at least, than off-gassing.

learningChem - 20-10-2012 at 14:20

For the record, the product I want is phthalic acid.

I'm going to try the reaction using 5% hno3 (I actually did try that but somehow the naphthalene and water evaporated, I can't figure out how...odd)

Also, my oil bath was heated to ~170C and still the diluted acid didn't boil. Is it possible that the molten naphthalene floating on top of it prevents it from boiling somehow?

kristofvagyok - 20-10-2012 at 14:22

Quote: Originally posted by learningChem

I'm going to try the reaction using 5% hno3

5% HNO3 is not even good to wash your hands with, it won't do anything.

cc. HNO3, 65 and above percent is used as an oxidant.

unionised - 21-10-2012 at 06:02

I think that the reference in that old book to oxidation to phthalic and oxalic acids is included as evidence for the structure. If you look elsewhere in the book it's clear they hadn't sorted out the structures of all the materials they used.

If that's the case then the yield could have been close to zero.

There are details for the oxidation of naphthalene to phthalic acid: it's a major industrial process.
http://www.lookchem.com/Chempedia/Chemical-Technology/Organi...

It's worth noting that aminonapthalenes and nitroaromatics are sometimes carcinogenic so it's probably worth avoiding them if you can. The yield of nitronaphthalene will be poor, but why take the risk?

If you want phthalic acid there are better ways to get it.

learningChem - 21-10-2012 at 13:30

>I think that the reference in that old book to oxidation to phthalic and oxalic acids is included as evidence for the structure.

Why do you think that's the case?

>If you look elsewhere in the book it's clear they hadn't sorted out the structures of all the materials they used.

The structures of which materials?

[Edited on 21-10-2012 by learningChem]

Nicodem - 22-10-2012 at 07:04

Quote: Originally posted by kristofvagyok

Quote: Originally posted by learningChem

I'm going to try the reaction using 5% hno3

5% HNO3 is not even good to wash your hands with, it won't do anything.

cc. HNO3, 65 and above percent is used as an oxidant.

15% HNO₃ is commonly used for oxidations. Less concentrated HNO₃ works as well, but 65% HNO₃ can cause electrophilic nitrations as side reactions where these are possible (like on naphthalene). Some NaNO₂ can be added to initiate the radical oxidation, but it is not indispensable because some nitric oxides will always spontaneously form upon heating (the catalytic cycle involves hydrogen abstraction by NO₂). This has been discussed and referenced already at this forum in the context of benzylic oxidations in a couple of other threads.

As far as I remember, at this forum, nobody yet found an example of naphthalene oxidation with HNO₃. Perhaps it is a confusion due to the oxidation of 1,2,3,4-tetrachloronaphthalene yielding phthalic acid.

Quote: Originally posted by Nicodem

By UTFSE you would get lots of previous discussions on this topic:

https://www.sciencemadness.org/whisper/viewthread.php?tid=17...
http://www.sciencemadness.org/talk/viewthread.php?tid=6573
https://www.sciencemadness.org/whisper/viewthread.php?tid=87...
https://www.sciencemadness.org/whisper/viewthread.php?tid=17...

kristofvagyok - 22-10-2012 at 08:42

I looked up this oxidation in SciFinder and non of the 16 methods used HNO3.

The most close was ceric-ammonium-nitrate in water or in ionic liquids for 1 hour at 100Celsius, but this also had nitronaphtalenes other products Can be found at:
Deleersnyder, Karen et al
From Tetrahedron Letters, 50(32), 4582-4586; 2009

Another method they used to oxidize it by hypochlorites in presence of heavy metal salts like CoO, FeO, RuCl3... The problem is that the journal where thi is found, errrm:
Faming Zhuanli Shenqing, 101434536, 20 May 2009

And the third accapteble method would be with ZnO in DMF with some oxygen. It needs 800W microwave for a few minutes, described at:
Gupta, Monika et al
From Tetrahedron Letters, 46(30), 4957-4960; 2005

UnintentionalChaos - 22-10-2012 at 08:59

I am somewhat surprised that there isn't V2O5 involved in the mentioned procedure. That seems to be a fairly standard catalyst for this sort of oxidation.

The problem with oxidizing naphthalene to phthalic acid is that you need a -lot- of oxidant as the extra carbons tend to become CO2. Even oxalic acid would require quite a bit of oxidant. Unless you're doing the industrial catalytic oxidation with oxygen, the amounts of oxidant are ridiculous (not to mention expensive). Workup would be difficult due to large solution volumes. I once did the math for using KMnO4 (assuming it even proceeds) and immediately threw out the idea.

Just buying phthalic anhydride (which by the experience of members here, often contains a fair amount of phthalic acid contaminant as well) seems like a much more reasonable approach if your goal is product and not exploring the method for the sake of learning. Personally, I've done the KMnO4 oxidation of o-xylene twice and I have no desire to repeat it again. Yields are not great, it uses lots of KMnO4 (but less than naphthalene would), and it takes quite a while. Alternately, you could buy KHP (potassium acid phthalate, a standard monoprotic acid widely used for titrations and frequently available on ebay) and acidify a solution to obtain phthalic acid. Lastly, you can buy or extract (from vinyl gloves) phthalate esters and hydrolyze them. I do an extraction on a large scale on my youtube channel (UC235) using a soxhlet extractor. Simply boiling shredded gloves in solvent is not nearly as efficient, but does work.

S.C. Wack - 22-10-2012 at 11:56

There are some HNO3 examples, IIRC the only one presented as useful was Beilstein&someone's from 188-something, they used sealed tubes and 25% HNO3.

edit:
Thorpe says @130C. Ann. 202, 215 (1880). Thorpe also mentions another ref that IIRC was much less harsh and measured very little yield.

[Edited on 22-10-2012 by S.C. Wack]

learningChem - 22-10-2012 at 16:09

Thanks to all who replied!

I wanted to try the method both for learning purposes, and to get some phthalic acid/anhydride. I haven't tried buying it here, but I haven't seen it listed so I'm not sure if it's easy to get (I suspect it isn't)

@Nicodem

I had found and read those threads before starting this one. As far as I remember there's no mention of direct oxidation of naphthalene with HNO3.

Yes, I saw the oxidation of tetrachloronaphthalene, and I actually chlorinated a tiny bit of naphthalene but didn't do anything with it because I then found the HNO3 ref. and thought that might be easier. I guess it isn't...

@UnintentionalChaos

So, even using KMnO4 yields are bad? Damn...

Nicodem - 23-10-2012 at 11:34

Quote: Originally posted by S.C. Wack

Thorpe says @130C. Ann. 202, 215 (1880). Thorpe also mentions another ref that IIRC was much less harsh and measured very little yield.

Finally we got this elusive reference.

They used HNO₃ with density of 1.15 g/mL which corresponds to 25% concentration (20 parts per 1 part naphthalene). Heated at 130 °C under autogenous pressure to obtain phthalic acid in 40% yield. Not bad for such a cheap oxidant and easy reaction work-up, but impractical from the equipment and safety perspective.

learningChem - 23-10-2012 at 14:52

Thanks Nicodem!

Now I'm really impressed with sciencemadness =]

Is "Thorpe" "Thorpe's Dictionary of applied chemistry"? (I'm going to get that one)

What about the other reference? Is it also an old reference that can be found online?

As to the method : Autogenous pressure means whatever pressure you get by heating a closed container at 130C? Sorry about letting my ignorance show : is that pressure too 'high'? Wouldn't some kind of pipe bomb work here?

hyfalcon - 24-10-2012 at 02:59

I wouldn't want to be around it if it let go, especially since that brew will most likely be carcinogenic.

Nicodem - 24-10-2012 at 09:38

Quote: Originally posted by learningChem

Is "Thorpe" "Thorpe's Dictionary of applied chemistry"? (I'm going to get that one)

What about the other reference? Is it also an old reference that can be found online?

It is the "Ann. 202, 215 (1880)" reference that I talked about. Thorpe's is just an encyclopedia where this reference was found by S.C. Wack. I suggest you to read that article, because it is a very detailed study on the oxidations of naphthalene and its simple derivatives (bromo, sulfonic acid, and nitro derivatives) with chromosufluric and nitric acids. You might find things that interest you there.

Quote:

As to the method : Autogenous pressure means whatever pressure you get by heating a closed container at 130C? Sorry about letting my ignorance show : is that pressure too 'high'? Wouldn't some kind of pipe bomb work here?

Yes, it means a closed vessel, like a sealed ampoule or autoclave (mind the corrosion!). Mind also that NO and NO₂ gases form during the oxidation, so the pressure increases with the conversion.
You can try the oxidation under reflux conditions, if you add some NaNO₂ and apply a balloon at the top of the condenser (to keep the partial pressure of NO₂ as high as possible). I doubt it would work, but if it would, it would likely require a couple of days of reaction time. I would also use a higher excess of HNO₃ and perhaps a 25-35% concentration. It is possible that the reaction only proceeds in the gas phase, because the usual oxidation mechanism with HNO₃ does not apply in the case of naphthalene (the Aryl-H hydrogens are nearly impossibly to abstract).

S.C. Wack - 24-10-2012 at 12:58

Thorpe is that Thorpe, which in this case was found under the naphthalene heading of the 1922 edition. It's one of the better sources of useful or semi-obscure references up to 1920. Google didn't show me that volume, or the relevant volume for the previous edition. Hmm. gallica.bnf.fr used to and likely still has it available for download. Gallica can be weird, e.g. the journal Compt. rend. (for the years 1835-1965) completely disappeared a couple weeks ago, all trace of it ever existing at the site were gone and all its pages 404. And now it's back.

B&K's article starts here:
http://books.google.com/books?id=JuktAAAAIAAJ&pg=PA213

I wonder if you need to look up boiling stones too.

learningChem - 24-10-2012 at 15:19

Nicodem, Thanks!

Now I'm completely discouraged =] But I do appreciate your help.

S.C. Wack, Thanks!

I read the phthalic acid entry in Thorpe. Regarding HNO3 oxidation of naph. it mentions "Beilstein a. Kurbatoff A. 202, 215"

I didn't find the Annalen der Chemie but I found this

Beilsteins Handbuch der organischen Chemie

http://archive.org/details/beilsteinshandb00richgoog

Both are in German - I thought Nicodem was talking about an article written in English.

>I wonder if you need to look up boiling stones too.

Hehe =]

Nicodem - 25-10-2012 at 06:53

Quote: Originally posted by learningChem

Regarding HNO3 oxidation of naph. it mentions "Beilstein a. Kurbatoff A. 202, 215"

Well, that's the reference we were discussing for the last 8 replies. You should pay more attention.

Quote:

I didn't find the Annalen der Chemie

If you want to find something, you need to try first: DOI: 10.1002/jlac.18802020205

Quote:

but I found this

Beilsteins Handbuch der organischen Chemie

That is Beilstein the database. Instead, we are discussing an article of which Beilstein was the coauthor.

If you have troubles doing literature work, I suggest you to read the forum guidelines. There is a long section on literature for beginners that might help you.

learningChem - 25-10-2012 at 10:41

Thanks. I'll check the section on literature.