Sciencemadness Discussion Board

Synthesis Phenol

KFC - 3-11-2006 at 16:12

If you neutralize Salicylic Acid with Sodium Hydroxide does it make Phenol?

Sandmeyer - 3-11-2006 at 16:25

Why are you posting this here and not in the beginings forum? Read the faq, do at least some own research before asking to be spoonfed. Your question can be answered by consulting any general organic chemistry book, online as well as offline.

[Edited on 4-11-2006 by Sandmeyer]

KFC - 3-11-2006 at 16:46

All you have to say is yes or no.

DeAdFX - 3-11-2006 at 16:50

Quote:
Originally posted by Sandmeyer
Why are you posting this here and not in the beginings forum? Read the faq, do at least some own research before asking to be spoonfed. Your question can be answered by consulting any general organic chemistry book, online as well as offline.

[Edited on 4-11-2006 by Sandmeyer]


You don't need to know organic chemistry to realize that an acid and a base form a salt and water.

enhzflep - 3-11-2006 at 17:00

Ahh, but that's exactly the point. Had said research been carried out before posting, then the question would never have been asked.

Nor would it 'have' to be answered.

If you don't understand calculus and have tried your best at it, no-one will begrudge you for asking for a few pointers. On the other hand, If one was to ask 'What's 1+1?' or 'What's 7*16?' then one could expect a response that was somewhat frosty, if there at all.

KFC, I understand your point of view - It takes almost no time to read or answer, HOWEVER when one compares the several minutes you may save by asking in such a forum with the amount of time spent reading the post be each and every person that comes across it, then it quite quickly takes (us) more time than it saves (you).

Look, don't get me wrong - I've got no idea if your synth would work. But searching for text that is already there is THE way to go. If this turns up no results, AND there's not a post that is appropriate then by all means - start a thread and ask away.

Regards.

EDIT: Crap! DeAdFX beat me to the punch. Of course acid+base = salt + water. I really must go to sleep overnight more often..

[Edited on 4-11-2006 by enhzflep]

KFC - 3-11-2006 at 17:21

All you have to say is yes or no.

Sandmeyer - 3-11-2006 at 17:58

Hey, asshole, all you have to do is to respect the forum, then maybe someone will help you...

KFC - 3-11-2006 at 18:40

Quote:
Originally posted by KFC
All you have to say is yes or no.


Sorry about this, my internet is screwy.

YT2095 - 4-11-2006 at 01:40

Quote:
Originally posted by KFC
If you neutralize Salicylic Acid with Sodium Hydroxide does it make Phenol?


KFC, at least TRY and work this out for yourself!

forget that it`s Salicylic acid, what if it was Sulphuric or Nitric acid, what would it make then?

now just change the suffix for either of those and you have your answer.

now having arrived at your answer, does it sound anything like Phenol to you?

Mr_X - 4-11-2006 at 08:05

Quote:
Originally posted by KFC
If you neutralize Salicylic Acid with Sodium Hydroxide does it make Phenol?


Nope, it will make sodium salicylate.

KFC - 4-11-2006 at 12:38

How do I make Phenol from Salicylic Acid?

And Thank You Mr_X

woelen - 4-11-2006 at 13:00

KFC, the way you behave in this thread will make your life over here on sciencemadness not very pleasant. If you continue acting like this, then you will simply be ignored by other members.

Show us, what you have found already on the properties of phenol and/or salicylic acid. Do you have some ideas of your own? Show that you can do some research yourself. If you provide us with input, then we will get more of a discussion, instead of just a spoonfeed session. Also, if you are really interested in the subject, then I strongly urge you to do some research, because it also gives you general knowledge, which comes in handy in many other situations. I built up my knowledge not by being spoonfed, but by actively reading, searching the Internet, experimenting and finally asking questions on forums. But this is the order in which things should be done.

The_Davster - 4-11-2006 at 13:49

Quote:
Originally posted by woelen


Show us, what you have found already on the properties of phenol and/or salicylic acid. Do you have some ideas of your own? Show that you can do some research yourself. If you provide us with input, then we will get more of a discussion, instead of just a spoonfeed session. Also, if you are really interested in the subject, then I strongly urge you to do some research, because it also gives you general knowledge, which comes in handy in many other situations. I built up my knowledge not by being spoonfed, but by actively reading, searching the Internet, experimenting and finally asking questions on forums. But this is the order in which things should be done.


If you don't show some of this in your next post KFC this thread is going to detritus.

Phenol Preparation - Question

laekkerBoy - 11-4-2010 at 13:47

Hey guys!

I am in kind of a trouble right now. I am planning on making a batch of TCPO and the only thing remaining in my process of synthesizing it, is the 2,4,6-Trichlorophenol. Making the TCP is not the problem, since it is rather easy and simple when starting from phenol. But making the phenol is difficult for me. I have been searching and thinking around for about two weeks now and my mind is fu*king up right now.
So here comes the question: Do you know of a rather easy way to prepare phenol? I was hoping that you could tell me a way starting from toluene, which I can get very cheap and very pure, and going further on to benzene. I really don't have any restrictions for the process, except from dealing with very high temperatures.
If it is a problem starting from toluene, I am willing to start from acetylene which I can get very easily too.
I am looking so much forward to your reply and thanks in advance!

The Kindest Regards,
Christian

mnick12 - 11-4-2010 at 14:04

Make phenol? Why not just buy some? After all it is rather cheap especially in the quantities you will need. But making it from either toluene or acetylene would be very tough and require alot of steps. I would do a decarboxylization of salicylic acid which is also cheap, and can be easily made from aspirin.

How do plan on chlorinating your phenol?And how do you know your final product is going to be 2,4,6-trichlorophenol and not some other polychlorinated phenol? Chlorinations are not very easy to control, and there is a very good possibility that your phenol will end up have PCB's and other very nasty and very carcinogenic polychlorinated phenols. You are probably better off just buying some.
Good luck, are you doing the glow stick reaction?

Jor - 11-4-2010 at 14:07

Start from sodium benzoate. When this is heated in a metal vessel benzene vapours evolve, wich should be condensed.
http://www.sciencemadness.org/member_publications/benzene_pr...
It should be redistilled due to impurities such as biphenyl.

Next nitrate this (Vogel) to nitrobenzene.

Reduce this to aniline with Sn/HCl or Fe/HCl, or best dithionite, by wich you avoid messing with the metals.

Diazotise, to obtain phenol (see Vogel).

But this is a a lot of work and yields aren't great. Are you sure you can't obtain phenol. It is sometimes sold on ebay as carbolic acid.

Lastly be careful with benzene, nitrobenzene, aniline and phenol. All quite unhealthy compounds.

JohnWW - 11-4-2010 at 14:16

Phenol is made industrially in large quantities, usually by firstly sulfonating C6H6 with oleum (fuming sulfuric acid, H2SO4 + SO3) to obtain benzenesulfonic acid, and then hydrolyzing this to C6H5OH with NaOH under pressure at 200ºC. It is used for further industrial chemical syntheses, as a lab reagent, and as the active ingredient of "carbolic soap" which has a distinctive odor of phenol.

It appears to be quite easily chlorinated all the way up to pentachlorophenol (PCP), C6Cl5OH, which is quite strongly acid, and which was once used as a non-metallic wood preservative, bonding to the cellulose in wood by esterifying the -OH groups. But PCP has since fallen out of favor for this use, because it is very water-soluble, being leached out of bare wood in the open by rain, and because it is highly liver-toxic and carcinogenic.

[Edited on 11-4-10 by JohnWW]

Nicodem - 11-4-2010 at 14:23

LaekkerBoy, welcome... but please be aware that you will receive more useful replies if you show you did some literature search yourself before asking others to do so. Even on this forum we have threads on the preparation of phenol. I do not remember if any experiments were described, but I'm pretty sure some useful reference was given. Also, avoid using acronyms unless you define them on first use. It brings too much confusion and only few will understand what you meant by TCP or TCPO.

If for some reason you want to prepare phenol yourself instead of just buying it (like other reagents you will need), then obviously doing it from salicylic acid (hydrolysed aspirin) is the simplest way. But if you need just any oxalate for a luminiscence experiment you might use some for which you need no stinking and toxic 2,4,6-trichlorophenol, for example:
Quote:
Synthesis of bis(6-butoxycarbonyl-2,4,5-trichlorophenyl)oxalate.
Li, Bin; Miao, Weirong; Cheng, Lubo.
Jingxi Huagong, 15 (1998) 23-25. (in Chinese)

Chem. Abstr. 128, 243798:

The title compd. was prepd. from chlorination of salicylic acid in acetic acid then in oleum giving 3,5,6-trichlorosalicylic acid, which was esterified with butanol and treated with oxalyl chloride. The title compd. is one of the necessary aryl oxalates used in chemiluminescent device.

The similar synthesis of 3,5,6-trichlorosalicylate esters from salicylic acid is described also in US4308395 (in English).

PS: When opening threads without any references given, please do so in the Beginnings section (where it is being moved anyway).

Edit: Did some literature search.

[Edited on 11/4/2010 by Nicodem]

chemrox - 11-4-2010 at 21:23

Good for you Nicodem. That was kind, thorough and very professional.

I edited this post to include the following 'green' synthesis.

http://www.aist.go.jp/aist_e/latest_research/2002/20020109/2...

[Edited on 12-4-2010 by chemrox]

laekkerBoy - 21-4-2010 at 03:00

Thanks a lot everyone!! Really, I am grateful!
After posting this thread, I have learned that the easiest way to synthesize Phenol is by the following route:

Toluene --(Friedel-Crafts)-->
Benzene --(Chlorination)-->
Chlorobenzene --(Raschig-Hooker)-->
Phenol.

I hope that this can help you guys too! I'll promise to post some pictures or a video of my reaction when I am able to do it.

As for the chlorination of Phenol to 2,4,6-Trichlorophenol, I am going to use a method previously posted on this forum:
Quote:

Originally posted by not_important at:
http://www.sciencemadness.org/talk/viewthread.php?tid=6757#p...

For 2,4,6-TCP just mix phenol with about 5 times its volume of dilute HCl, warm slightly to get the phenol to form a solution, then bubble Cl2 through the mixture with stirring; TCP will precipitate out. Set up your chlorine generator to make 3 moles of Cl2 for every mole of phenol. Remember it's forming HCl, the solution will grow more acidic. Filter off the TCP and wash with cold (ice) water. Recrystallise from boiling water or water+alcohol solution (it's really soluble in MeOH, EtOH, and acetone). Extra purification might be crystallisation from hot ligroin or similar hydrocarbon, or fractional freezing where impurities tend to remain in the liquid portion. There's got to be a number of references around for preparing it.


Nicodem: I am sorry for that I didn't tell any pages or so with literature. I'll remember that for the next time.
I think that the salicylic acid way is too expensive when you think of the final product, but thanks anyways!

A final applause to all of your guys who have answered my question!!

The Kindest Regards,
Christian.

not_important - 21-4-2010 at 03:55

The Raschig phenol process is little used nowadays, having fallen out of favour in the 1970s. As it takes place in the vapour phase at temperatures in the low-to-mid 400 C range, and with incomplete conversion, it is not too convenient for amateur application; it really is an industrial scale process.

The older method using fusion of benzenesulfonic acid with alkali hydroxide is easier for small scale production. Even though the temperatures used are in the same range, it's much easier to to melt and stir a few hundred grams of reactants than to pass them over catalysts as gases.

Toluene to benzene via FC catalyst works, but can be tedious. Benzene chlorination isn't too bad, but then you're faced with the hydrolysis issue.

laekkerBoy - 21-4-2010 at 04:44

Thanks a lot for the suggestion!
I am unfortunately not able to obtain sulfonic acid ATM to synthesize the benzenesulfonic acid. If i was, it would probably be my preferred way of obtaining Phenol, so thank you very much!

DJF90 - 21-4-2010 at 05:14

Well for a start, you don't use sulfonic acid to synthesise benzenesulfonic acid... Paracetamol is a convenient OTC source of p-aminophenol (by hydrolysis after extraction) which can then be diazotised and heated in ethanol to effect reduction to phenol. This can then be trichlorinated under appropriate conditions to the desired compound. Ok its a bit round the houses, but it'll work nicely and provide you with the compound you desire from relatively easy to obtain starting materials.

[Edited on 21-4-2010 by DJF90]

UnintentionalChaos - 21-4-2010 at 06:18

Try the orgsyn prep for p-hydroxybenzoic acid. One equivalent of phenol distills off during heating and can probably be condensed readily if desired.

Salicylic acid and potassium carbonate are readily available.

[Edited on 4-21-10 by UnintentionalChaos]

laekkerBoy - 21-4-2010 at 06:25

Thank you! I'll try to find something about that.

Nicodem - 21-4-2010 at 12:49

Quote: Originally posted by laekkerBoy  

After posting this thread, I have learned that the easiest way to synthesize Phenol is by the following route:

Toluene --(Friedel-Crafts)-->
Benzene --(Chlorination)-->
Chlorobenzene --(Raschig-Hooker)-->
Phenol.

I hope that this can help you guys too! I'll promise to post some pictures or a video of my reaction when I am able to do it.

That is supposed to be the easiest way to synthesize phenol? Are you trying to appear funny or make fun of us?
Quote:
Nicodem: I am sorry for that I didn't tell any pages or so with literature. I'll remember that for the next time.

There already was a next time and you did not remember! What is the reference for the Friedel-Crafts disproportionation of toluene?
Quote:
I think that the salicylic acid way is too expensive when you think of the final product, but thanks anyways!

This makes no sense. You would go investing money onto building an apparatus able to withstand the pressure required for transforming chlorobenzene into phenol, but have troubles acquiring salicylic acid? You don't mind doing research into the transformation of toluene into benzene, but have troubles doing a known decarboxylation of salicylic acid? If it is about the price, then why don't you just buy phenol? Or buy 2,4,6-trichlorophenol for that mater? Maybe you should simply get serious, because at the moment it appears as if you were some teenager not knowing what to do with your time and yourself.

bbartlog - 22-4-2010 at 05:07

There is a previous thread regarding phenol (probably multiple ones), including one I started when I wanted some advice on what sort of gunk I had made by reacting sodium hypochlorite and aspirin. See http://www.sciencemadness.org/talk/viewthread.php?tid=13026#...
Dry pyrolysis of sodium salicylate will get you phenol. One of the members here (benzylchloride1) describes his procedure in the abovelinked thread.
Further, it appears to me that it is not necessary to proceed through phenol as such in order to obtain 2,4,6-chlorophenol. I notice (again in the above thread) the following comment from Nicodem:
Quote:
The chlorination of salicylic acid proceeds in this order: 5-chlorosalicylic acid (and some 3-chloro regioisomer), 3,5-dichlorosalicylic acid, 2,4,6-trichlorophenol (via ipso electrophilic substitution)


So rather than synthesize phenol it seems that you might be better off chlorinating salicylic acid directly, with the third chlorination providing decarboxylation at the same time. Exactly what method of chlorination you would want to use is an interesting question, but a little research would surely provide you an answer.
Quote:
I think that the salicylic acid way is too expensive when you think of the final product, but thanks anyways!


I have no idea what country you are in, but here in the USA I can go to the drugstore and buy plain old aspirin at a price that comes out to about $7 per mole of (acetyl)salicylic acid. Which as organic reagents go is ridiculously cheap, and given that this is a pharmaceutical it's probably even fairly pure once the binders/additives are removed.



not_important - 22-4-2010 at 05:34

Indeed, purchase ordinary generic uncoated aspirin and you have a low cost source that requires little workup.

The main exception is in Japan, where in most places you have to buy little boxes with only a few tablets and highly market p, from little mom&pop stores.

Nicodem - 22-4-2010 at 06:32

Quote: Originally posted by bbartlog  
Further, it appears to me that it is not necessary to proceed through phenol as such in order to obtain 2,4,6-chlorophenol. I notice (again in the above thread) the following comment from Nicodem:

Quote:
The chlorination of salicylic acid proceeds in this order: 5-chlorosalicylic acid (and some 3-chloro regioisomer), 3,5-dichlorosalicylic acid, 2,4,6-trichlorophenol (via ipso electrophilic substitution)

I based that mostly on the analogy of nitration where nitration of salicylic acid with fuming HNO3 gives picric acid and the nitration of 3,5-dichlorosalicylic or 3,5-dibromosalicylic acids gives 2,4-dichloro-6-nitrophenol and 2,4-dibromo-6-nitrophenol correspondingly (see examples cited in Chem. Rev., 40 (1947) 117–140). The ipso aromatic electrophilic substitution of the carboxylic group occurs quite commonly on some substrates, so I thought it was a general phenomena for salicylic acid. Now that I searched for trichlorination of salicylic acid I can not find any such reaction. In highly acidic the product is 3,5,6-trichlorosalicylic acid as described in the two references given upthread. I would expect that under basic conditions (chlorination of the phenoxide) there should form 2,4,6-trichlorophenol, but I can not find any such example in the literature. There are only three 19th century papers describing what appears a two step preparation 2,4-dichlorophenol by chlorinating salicylic acid followed by treatment with lime for the retro-Kolbe-Schmitt reaction. Unfortunately, I can't get the original papers and this is all info I can get out of Beilstein. On the other hand, the bromination of sulfosalicylic acid gives 2,4,6-tribromophenol (J. Am. Chem. Soc., 43 (1921) 303–315). The reaction can be performed one-pot from salicylic acid.

DJF90 - 22-4-2010 at 08:08

I'm wandering if someone can help me out. I understand ipso substitution very well, or at least I though I did. In an attempt to write a response to this thread I found myself unable to explain why the ipso substitution of trinitrobenzoic acid takes place - a very well known textbook reaction - as in the formation of the wheland intermediate this requires the formation of the arenium ion directly adjacent to the electron withdrawing nitro group! Now this should be massively disfavoured, so the reaction is either kinetically controlled, or thermodynamically driven (although I cannot see how so).

Salicylic acid however does not suffer from such problems, as the phenolic group stabilises the wheland intermediate and all is above board from there. Bromination should be analogous, but details may be scarce in the literature because nitration is the main reaction that was studied regarding Ipso substitution.

EDIT: Sussed it. Former occurs via different mechanism (SE1) compared to SEAr. o-nitro substituents aid this mechanism, as the sp2 anion is in the plane of the ring and so oblivious to mesomeric effects: the NO2 groups provide good inductive withrdrawal to stabilise the anion, and as the inductive effect decreases with distance, it explains why ortho EWGs work very well.

A corrolary of this appears thusly: Both o- and m-nitrobenzoic acids could possibly yield nitrobenzene by refluxing in acid (via the two different mechanistic pathways). This would be a nice amatueristic route, especially as nitration of toluene and subsequent oxidation would yeild the former, and nitration of methyl benzoate and hydrolysis would lead to the latter. Interestingly the hydrolysis step with methyl m-nitrobenzoate may even be done in situ using acid to effect hydrolysis and decarboxylation in one step

[Edited on 22-4-2010 by DJF90]

White Yeti - 1-8-2011 at 12:06

How about making phenol from benzene and Fenton's reagent? It's an obscure way to make phenol, but it seems to work.

UnintentionalChaos - 1-8-2011 at 14:45

Quote: Originally posted by White Yeti  
How about making phenol from benzene and Fenton's reagent? It's an obscure way to make phenol, but it seems to work.


To avoid destruction of the phenol, the reactants need to be extremely dilute and you need a very large excess of benzene, from what I remember reading.

White Yeti - 1-8-2011 at 15:09

"To avoid destruction of the phenol, the reactants need to be extremely dilute and you need a very large excess of benzene, from what I remember reading."
That makes sense.
What concentration would you recommend?

UnintentionalChaos - 1-8-2011 at 21:34

Quote: Originally posted by White Yeti  
"To avoid destruction of the phenol, the reactants need to be extremely dilute and you need a very large excess of benzene, from what I remember reading."
That makes sense.
What concentration would you recommend?


That makes recovery of the phenol from the reaction mixture very difficult, and I am suggesting that you don't bother pursuing it as a preparative technique unless you can find some literature on it.

White Yeti - 2-8-2011 at 06:11

"That makes recovery of the phenol from the reaction mixture very difficult, and I am suggesting that you don't bother pursuing it as a preparative technique unless you can find some literature on it."

I wasn't even planning on making it, for the simple fact that benzene and phenol are about the same price. Any reaction pathway that would yield phenol from benzene is not worth trying out. Both substances are dangerous/ flammable/ carcinogenic, I'd rather buy phenol than make it.

I was just suggesting Fenton's reagent as an unexplored possibility that none of the other users have mentioned (probably for a good reason).