Sciencemadness Discussion Board - Oxidizing Naphthalene to Phthalic anhydride

Oxidizing Naphthalene to Phthalic anhydride

TheNaKLaB - 30-10-2011 at 23:47

I was reading up about Naphthalene about some properties and I found out that it can be oxidized to Phthalic anhydride.

"Oxidation with chromate or permanganate, or catalytic oxidation with O2 and a vanadium catalyst, gives phthalic acid"

I found this information on Wikipedia.

Would there be some way to directly oxidize the Naphthalene to Phthalic anhydride using Potassium Permanganate? Would there be a sensible method for oxidizing it? Eg, melting the Naphthalene with Potassium Permanganate.

Chemistry Alchemist - 31-10-2011 at 10:15

wasnt i the one who told u about this synthesis?

[Edited on 31-10-2011 by Chemistry Alchemist]

Takron - 31-10-2011 at 10:24

The way I would start is to dissolve a stoich. amount of both chems in water. The Naphthalene is only very slightly soluble in the water but I would venture a guess that as you reflux the mix, the naphthalene would react and then more naphthalene would dissolve into the water.

But I did some poking and found this.
''Manufacturing methods in the nineteenth century included oxidation of naphthalene tetrachloride with nitric acid, or, better, oxidation of the hydrocarbon with fuming sulfuric acid, using mercury or mercury(II) sulfate as a catalyst."

Also this -> Patent

Chemistry Alchemist - 31-10-2011 at 11:02

what would be the best way to obtain naphthalene tetrachloride?

Getting NTC

Takron - 31-10-2011 at 12:48

Quote: Originally posted by Chemistry Alchemist

what would be the best way to obtain naphthalene tetrachloride?

This?

TheNaKLaB - 31-10-2011 at 13:49

I dissolved some Potassium Permanganate in water, then added some Naphthalene and boiled it until the Naphthalene melted. I heated the Naphthalene and Potassium Permanganate solution for about 20 minutes. After the solution cooled, the Potassium Permanganate changed a darker red/brown rather than the Purple it normally is. It also settled to the bottom of the beaker. I still have yet to check if there's any Phthalic anhydride by drying out the Potassium Permanganate precipitate/settlement and heat it until the Phthalic anhydride sublimes.

bfesser - 31-10-2011 at 13:59

Your product would likely be present as dipotassium o-phthalate. Try filtering to remove MnO2, acidify, filter, dry, then sublime the acid to the anhydride.

[edited to remove typos caused by the damn cat laying on the keyboard]

[Edited on 10/31/11 by bfesser]

Squall181 - 31-10-2011 at 17:17

Yes Please let us know if you can precipitate phthalic acid from your solution by acidifying.

If this works this would be a much easier than having to boil boxes of vinyl gloves to extract Bis(2-ethylhexyl)phthalate.
If I can find some moth balls I will give this a try this weekend and report.

TheNaKLaB - 31-10-2011 at 18:05

I think I might have some success! The Potassium Permanganate seemed to react with the Naphthalene, because I have quite a bit of Manganese Dioxide that precipitated.

The Phthalic acid should precipitate when I acidify it, right?

I'll definitely be making a video on the process (If it actually ends up working).

Lastly, does anyone know the equation for reacting Naphthalene with Potassium Permanganate to Dipotassium Phthalate?

[Edited on 19-09-2011 by TheNaKLaB]

mnick12 - 31-10-2011 at 18:52

Phthalic anhydride? You mean phthalic acid. Anhydrides cannot be precipitated from aqueous solutions.

Chemistry Alchemist - 31-10-2011 at 20:05

The procedure doesn't creat phthalic anhydride, you need other steps to obtain. The product, when naphthalene is oxidized it will make dipotassium o-phthalate and manganese dioxide which needs to be filtered. The dipotassium o-phthalate then needs to be acidified to precipitate phthalic acid and potassium salt which needs to be filtered and washed, you the. Need to dehydrate the acid to the anhydrous state and collect the needle like crystals, this is the synthesis I've been trying to work out for the last 3 months for my first organic synthesis, looks like I'll need to find a new one

[Edited on 1-11-2011 by Chemistry Alchemist]

TheNaKLaB - 31-10-2011 at 20:16

I accidentally wrote anhydride instead of acid. Besides that, what would be the equation?

Takron - 31-10-2011 at 20:21

Yay, so my idea worked for the most part?

smuv - 31-10-2011 at 20:45

Another product worth considering:
http://www.orgsyn.org/orgsyn/prep.asp?prep=cv2p0523

[Edited on 11-1-2011 by smuv]

Takron - 1-11-2011 at 10:26

What's that used for? I checked on it and all I found were tests for cholesterol and fatty acids.

Squall181 - 1-11-2011 at 16:27

Well lately it has been getting a lot of attention because it is used in Nurdrage's synthesis of Luminol, at least that's what I think.

Chemistry Alchemist - 1-11-2011 at 17:04

Also had a use t make phenolphthalein.

Chemistry Alchemist - 1-11-2011 at 17:28

So what is teh chemical equasion for this? for just the oxidation of Naphthalene carrys out as the following
8 C10H8 + 21 O2 = 10 C8H6O4 + 2 H2O

But with teh added potassium permanganate, what is actually happening here? i tryed for ages to figure it out but my results always came out negitive... anyone know?

TheNaKLaB - 1-11-2011 at 18:22

That equation is unbalanced, but that's the basic idea for the reaction?

I need to find out the reaction equation for the oxidation of Naphthalene and Potassium Permanganate.

Chemistry Alchemist - 1-11-2011 at 19:24

U sure its unbalanced? i use a program where you type in ur equation and if its balanced then it comes out Like this 8 C10H8 while if its unbalanced then the whole thing looks like this ? C10H8

Yeah, id like to know the reaction equation as well for it as well

TheNaKLaB - 1-11-2011 at 19:50

Wait, sorry, that was a misunderstanding

I stuffed up aha!

What program do you use?

Chemistry Alchemist - 1-11-2011 at 20:18

Thats kk

i tryed to use teh program to work out the Potassium Permanganate and Naphthalene but couldnt work it out... I use EBAS, its a program that calculates how much of each chemical you need for a reaction... its really good, but its a trail version, the one the trial is up you can still use it but the data base has been cut down so you need to keep typing in the formula instead of searching for it...

http://www.chembuddy.com/?left=EBAS&right=buy

I havent came across a patch for it yet so thhe only way to get full version is buying

Takron - 1-11-2011 at 22:16

Quote: Originally posted by Squall181

Well lately it has been getting a lot of attention because it is used in Nurdrage's synthesis of Luminol, at least that's what I think.

I was speaking about smuv's other product worth considering. I'm well aware of Phthalic Anhydride's popularity as of late

.

I'm actually going to be doing a video comming up here soon on polymers using Phthalic Anhydride.

scrambles - 2-11-2011 at 18:07

permanganate would probably be the best option. you can buy the stuff at Sears (tm).

EDIT: Someone find out how to isolate napthalene from vm&p naphtha.

[Edited on 3-11-2011 by scrambles]

mr.crow - 2-11-2011 at 19:11

Ummm naphtha does not have naphthalene. If it did it would smell really bad and leave residues

smuv - 2-11-2011 at 21:12

Probably using a larger excess of base will avoid this side product. You can imagine, that under harsh enough conditions, hydroxide would add into the a-ketoester, to form the deprotonated acetal. The deprotanated acetal could then go on to add into KMnO4. A mechanism like this is only favored in strongly basic conditions (notice the orgyn procedure is not using much base, balance the equation and you will see).

Additionally acidic conditions would totally avoid this product, but it is also more likely that you will get cleavage of you phthalic acid product under these conditions.

One thing that comes to mind, is it may be possible to produce phthalic anhydride from xylenes (mixed isomers) by oxidizing the xylene, and sublimating the product. I assume that the phthalic anhydride formed has a much higher vapor pressure than either iso or terephthalic acid. This difference in vapor pressures may provide a means of isolating only phthalic anhydride from this mixture.

Takron - 2-11-2011 at 23:20

Quote: Originally posted by smuv

...it may be possible to produce phthalic anhydride from xylenes (mixed isomers) by oxidizing the xylene, and sublimating the product...

Would this be achieved like the oxidation of toluene to benzoic acid and MnO2? Xylene and KMnO4 combined and refluxed together and then filtered with drying then sublimate it out?

Would you have any ideas for a decent but not too exotic phase transfer catalyst for these reactions? I thought maybe a little bit of detergent or cascade or something but I figured something better must exist.

Chemistry Alchemist - 3-11-2011 at 08:55

I said in a previous post about a a stoichiometry calculator but hadn't found a crack or patch for it, well i think i have cracked it... on this website below alot of shizz there is a button saying Get Crack, click on it, will start downloading a rar. and just extract to desktop or where ever you want it, im 90% sure its the full version, looks like it to me because i could never be able to save data on it

great tool for amateurs like me

http://cracks.bz/download_EBAS.1.0.1.63.cracked-SND_crack_se...

Takron - 3-11-2011 at 09:04

Dude that site looks like a virus hotbed.

Chemistry Alchemist - 3-11-2011 at 09:59

i checked it out and its fine, no viruses found, u dont have to do it, just a site i found with a crack that works, its VERY hard to find a patch for a program that isnt that popular compared to other software i have tried to crack

Nicodem - 3-11-2011 at 10:15

There is no need to crack anything. EniG. Chemistry Assistant is a calculator that can parse empirical formulas and treat them as MW. It is a freeware and very good with an easy interface. It also has a gadget to calculate the amounts required for preparing solutions of many inorganic and a few organic reagents with the density tables integrated.

Chemistry Alchemist - 3-11-2011 at 10:18

Thanks, I'll check that out when it's morning time

Neil - 4-11-2011 at 07:46

http://www.sciencemadness.org/talk/viewthread.php?tid=6573

"...phthalic anhydride from naphthalene"

Chemistry Alchemist - 15-11-2011 at 01:54

Ok so i was ment to get some glassware from Panchie but he still hasn't u2u'd me to say hes posted it, so i was wondering, could i use stainless steel pot with lid to boil the Naphthalene with eh Potassium Permanganate? or would the stainless steel do something to the reaction?

Nicodem - 16-11-2011 at 10:21

Given you provide no reference, I can only guess you are talking about the synthesis of phthalaldehydic acid as described in Org. Synth.?

Quote: Originally posted by Chemistry Alchemist

Ok so i was ment to get some glassware from Panchie but he still hasn't u2u'd me to say hes posted it, so i was wondering, could i use stainless steel pot with lid to boil the Naphthalene with eh Potassium Permanganate? or would the stainless steel do something to the reaction?

Neglecting the obvious problem of oxidative corrosion, how the hell are you going to reflux in a pot with a lid? (And why would you want to do that!?)

Chemistry Alchemist - 16-11-2011 at 17:30

Dude, I'm just asking a simple question which needs a yes or no explination... What's going to be so corrosive in the reaction? I just really want to do this reaction!

Neil - 16-11-2011 at 18:45

Nicodem is actually being very nice to you, though it may seem back handed.

I think his answer would best be paraphrased as; No.

If you can not reflux the pot then the question of corrosion is largely superfluous. The lid is not going to work as a reflux.

Google offers this, and many other tantalizing titbits;
"In neutral and alkaline solutions, sodium permanganate is not corrosive to iron, mild steel or stainless steel. However, chloride corrosion of metals may be accelerated when an oxidant such as F2PP-98 Potassium Permanganate is present in solution. Plastics such as polypropylene, polyvinyl chloride Type I (PVC I), epoxy resins, fiberglass reinforced plastic (FRP) and TFE, and Tefzel EFTE are best. Refer to Material Compatibility Chart."

http://www.hepure.com/potassium-permanganate.html

Chemistry Alchemist - 16-11-2011 at 21:38

Sorry if I took it the wrong way, I was really just looking for a yes or no answer anyway