Sciencemadness Discussion Board

Uses for phenol

Random - 17-1-2011 at 11:18

I have some phenol, but when I look into something, I can't think of any reactions with it except salicylaldehyde from phenol, chloroform and NaOH solution. Does someone know some more reactions that could be useful for home chemist?

I was thinking about making aniline from phenol and ammonia, but it seems that it requires high temperatures. Is there also alternative route to it?

Also, if someone knows more reactions I could perform with it, please let me know. Thanks.

UnintentionalChaos - 17-1-2011 at 11:31

Make phenolphthalein.
Make trichlorophenol and use that to make bis-(trichlorophenyl)oxalate.
Salicylaldehyde can also be made with the handy Mg-mediated o-formylation reaction in prepublication and that can
be used to make salen ligands or a benzofuran (http://en.wikipedia.org/wiki/Benzofuran#Laboratory_methods).
O-acylate it and perform a fries rearrangement on the product (or FC acylate it, which is essentially the same thing in one step).
Make an allyl ether and do a Claisen rearrangement.
Use the phenolate as a nucleophile to make a phenyl alkyl ether with the Williamson ether synthesis.
Nitrate to picric acid if you're into that sort of thing.

spirocycle - 17-1-2011 at 12:21

how would you make trichlorophenol form that?

entropy51 - 17-1-2011 at 13:48

Phenol is easily mononitrated with dilute HNO3. The o and p isomers are separable by steam distillation. A nice exercise for beginners.

Phenol is easily condensed with HCHO to form Bakelite, one of the first plastics.

Check the index of organic chemistry textbooks, including Vogel.

[Edited on 17-1-2011 by entropy51]

Make Bakelite plastic

The WiZard is In - 17-1-2011 at 13:58

This was basement lab tested by Id a whole bunch of years ago.
What's left of my memory sez - it smelled good too.

Popular Science April, 1946

http://tinyurl.com/63r3mmd

I maybe have an original of this, if'n there is enough
interest I could scan it.

Random - 18-1-2011 at 13:19

Synthesis of salicylaldehyde with Mg is interesting but it uses H2SO4 that I cannot easily obtain.
I will make TCP when I wil get more friendly with chlorine.
Nitration of phenol is interesting, I would then reduce the nitro group to amino and then make some more compounds from aminophenol. I read that nitrophenols are very toxic, now how could I avoid being poisoned? I have nitrate salts and HCl, could a mix of these two be used instead of nitric acid? Also I want to be sure to not prepare explosive compound because I am interested in chemistry, not in blowing up myself.

ScienceSquirrel - 18-1-2011 at 13:50

The best way to 4-aminophenol for the home chemist is from paracetamol.
It is easily made from paracetamol tablets as the hydrochloride by extraction and hydrolysis with hydrochloric acid.
The hydrochloride crystalises readily as white needles and then you can make things from there.

UnintentionalChaos - 18-1-2011 at 13:52

Quote: Originally posted by Random  
Synthesis of salicylaldehyde with Mg is interesting but it uses H2SO4 that I cannot easily obtain.
I will make TCP when I wil get more friendly with chlorine.
Nitration of phenol is interesting, I would then reduce the nitro group to amino and then make some more compounds from aminophenol. I read that nitrophenols are very toxic, now how could I avoid being poisoned? I have nitrate salts and HCl, could a mix of these two be used instead of nitric acid? Also I want to be sure to not prepare explosive compound because I am interested in chemistry, not in blowing up myself.


No, HCl is oxidized by nitrates to aqua regia (poor man's aqua regia if you're in the precious metals refining community)

Wear apropriate safety gear when working with nitrophenols. All nitro compounds are pretty toxic. Don't get them on your skin.

mario840 - 19-1-2011 at 07:32

making 2,4-dinitrophenol , good old herbicide

Chemistry Alchemist - 22-9-2011 at 04:16

Quote: Originally posted by ScienceSquirrel  
The best way to 4-aminophenol for the home chemist is from paracetamol.
It is easily made from paracetamol tablets as the hydrochloride by extraction and hydrolysis with hydrochloric acid.
The hydrochloride crystalises readily as white needles and then you can make things from there.


Can you convert 4-aminophenol back into phenol?

mario840 - 22-9-2011 at 05:36

Quote: Originally posted by Chemistry Alchemist  


Can you convert 4-aminophenol back into phenol?



of course this is called deamination , you react 4-aminophenol via sandmeyer reaction with NaNO2 and HCl or H2SO4 to diazonium salt and then add hypophosphorous acid H3PO2 to replace amine group to hydrogen.

1.JPG - 5kB

Chemistry Alchemist - 22-9-2011 at 05:49

Is there like a write up on this step by step precess or not? also, i brought some 85% phosphoric acid, how would i get Hypophosphorous Acid?

barley81 - 22-9-2011 at 09:36

You can't make hypophosphorous acid from phosphoric acid. Sodium hypophosphate can be made by the disproportionation of white P in sodium hydroxide (caution: Phosphine is produced). It can be converted to the acid with ion-exchange resin, read Brauer in the forum library for more details. It's hard to buy as it's restricted by the DEA.

Chemistry Alchemist - 22-9-2011 at 09:41

is there another acid i could use or is that the only one?

Chemistry Alchemist - 22-9-2011 at 09:59

instead of Hypophosphorous Acid?

DJF90 - 22-9-2011 at 10:18

Courtesy of Larock's Comprehensive Organic Transformations...



Capture.PNG - 37kB

Chemistry Alchemist - 22-9-2011 at 10:21

sorry if i sound like a dumb ass, but could u put it english a bit :/

barley81 - 22-9-2011 at 11:38

The reagents used for the deamination are on the left, and their references are on the right. Find one that you like. One is formaldehyde, that might be easy and cheap to get (though nasty). Get access to the references section if you don't already have it, and ask for it there, or look around to see if it's there already.

But it's too expensive to be worth anything. You should be able to make phenol from aspirin (WalMart, 500 pills for $4).


[Edited on 22-9-2011 by barley81]

Chemistry Alchemist - 22-9-2011 at 17:26

Quote: Originally posted by barley81  
You should be able to make phenol from aspirin (WalMart, 500 pills for $4).




as in straight from aspirin or take few other steps to getting it?

barley81 - 22-9-2011 at 18:12

Other steps: hydrolysis with base and workup to salicylic acid, decarboxylation to phenol.

Chemistry Alchemist - 22-9-2011 at 21:01

So could i just heat Salicylic Acid to decompose it to phenol or is there another process to do so?

Nicodem - 23-9-2011 at 06:14

Have you ever considered to UTFSE?

Chemistry Alchemist - 23-9-2011 at 06:27

yeah i have been the whole time, most of the time there is what im looking for but its a paid pdf, and i cant seen to get around the paid area and there are no torrents of those pdf's so i cant download them, ScienceMadness is a home for people who like to discuss science topics and google doesnt tell me what i want to here :S

Nicodem - 23-9-2011 at 06:31

If you would ever UTFSE you would have known that it stands for Use The Forum Search Engine!

Chemistry Alchemist - 23-9-2011 at 06:32

Sorry, i have been regularly using the forum search engine, but it doesnt put it into words i understand...