UC235 - 2012-10-19
p-Toluenesulfonic acid monohydrate is prepared by sulfonation of toluene with concentrated sulfuric acid in a Dean Stark setup for water removal. The reaction mixture is worked up by formation of the monohydrate and recrystallization. The crude product is dissolved in a minimum of water that is then saturated with gaseous HCl to reduce the solubility of the product, which crystallizes out on cooling. The product is dried over NaOH and sulfuric acid to remove both water and HCl. Yield is 57.6% based on sulfuric acid of a slightly off-white powder melting at 99-103C (lit m.p. 103-106C). Water is likely the major contaminant. Procedure is essentially that found on page 875 of Vogel's Textbook of Practical Organic Chemistry, 5th edition. The intro music clip is from "Stealing Fat" by The Dust Brothers. I believe this falls under fair use.
I guess I can understand that. Well either way, keep making videos..... and I'll keep watching. haha
Thank You very much!!! You help me a lot (learning chemical vocabulary too ;) )
Can you show how to purify hardware store toluene ? :D
You have such great videos... I'm not sure why you haven't had more exposure.
Just tried this one, again. Used roughly 1.2 Moles Toluene to 0.5 mole of H2SO4, to give 87.6g yield of crude product.
Your videos are spectacular, do you perform these as a hobby?
Why is the sound so low?
A great video. Question about tubing. From the HCl generator to the reaction vessel you use a gnarly piece of tubing, what is it made from? Then, the piece to the scrubber looks like an ordinary plastic material. Is that because in this segment, any HCl is less concentrated? And finally, when do you need to be concerned about what is entering your vacuum pump, i.e. could vapors damage the pump? I think that Dean Stark trap is such an elegantly simple device, how perfect in this situation!
Given that the TsOH is a strong acid, the solid monohydrate is probably the "salt" Hydronium Tosylate. Your argument is still valid, though. The HCl increases the amount of solvated H3O+ around and forces the hydronium salt out of solution
What is the pKa of p-Toluenesulfonic acid?
Oh, missed the part about the pump. I'm using a teflon diaphragm pump. Everything that the vapors touch is fluoropolymer and it doesn't use oil, so it's inert to just about absolutely everything. I am more concerned about breathing the fumes coming out the other end of the pump
Holy-Terrorist:>*=* I want to make chemistry stuff of not stuff chearched :p
What are you going to use this for?
Hi, first of all I want to thank You,that You do such great videos. But I have a problem.I've synthesized p-toluenesulfonic acid and my product melted (probably, coz i dont have desiccator) before recrystallization (my procedure said that I must leave it for 1 week).Of course You said that it will,but I have a question: will pure (like from the store) p-toluenesulfonic acid monohydrate melt (absorb water), when I leave it in open air (for example:in the room)? Thx for help,sorry for my English
Distill to remove any major contaminants and then then wash with cold concentrated sulfuric acid to remove thiophthenes.
DId this sulfonation as per the video. Made the same mistake: You have to chill the TsOH in an Ice bath while you gas it. Otherwise, the heat keeps the solution liquid, and you absorb Too much HCl. - then you have to take weeks to dry it.
one more thing on this. After you vacuum filtered the final product, there was a filtrate whose color looked similar to the original aqueous solution. Does that mean there was still some TsOH in solution? Or is this the o-product? What can you do to further recover this?
Is refreshing to see that you site Vogel is your source most of the other videos I’ve seen on this subject do not
Will MgSO4 or Na2SO4 (anhydrous) absorb the water sufficiently to avoid the need for the Barrett/Dean-Stark Trap? They should both be stable in the environment and both absorb shitloads of water
Holy-Terrorist:>*=* Cool, you have a chance to make it! *=* I never making real chemistry of i haves a parents. *=* That very long time to look the video, i just want look the synthesis in video.
22:14 WRONG! How could you state any "nucleofilic attack by benzene ring"??? It is electrophilic reagent is attacking benzene ring, benzene ring can't attack anything here! Benzene sulfonation is one of examples of electrophilic substitution rection. Here is just electrophile, no nucleofiles. Benzene ring is stable and doesn't need anything or anyone and is inert to anything around. You need high temperature and/or highly reactive electrophile to force benzene pi-system to join into reaction.
what if you dont have a dean stark aparatus can you just distill the water toluene azeotrope and replenish the round bottom with fresh toluene?
How long will it take? to producing
Hey I have a quick question. On those Sand-Core filter funnels at around 15-40 Micron, do you recommend using filter paper on top of the core as well? What are the different conditions that one decides to use filter paper along with it, if any?
Curious that TsOH should form a "salt" with hydronium. I was under the impression that the water was acting in a way similar to water of crystallization, but TsOH is indeed more acidic than hydronium, so a hydronium "salt" is within the realm of possibility.
I'm not sure that anyhydrous CuSO4 is an effective drying agent at these high temperatures. The reaction will proceed even without azeotropic drying (just simple reflux), but conversion will not go to completion.
Yes, reagent grade p-TsOH is also very hygroscopic, and if left exposed to moist air, will deliquesce (that is the word you are looking for rather than melt).
grate vidios but thay are a bitt long and tidius to watch
The tubing coming from the generator is plain old fiberglass reinforced vinyl tubing. It looks opaque because it has seen many solvent fumes, wet chlorine, and wet HCl in its time. The smaller tubing is also vinyl, but has seen a lot less abuse. You can however, see some bromine stains on the end near the trap.
I work in a QC lab for a chemical factory that produces p-TSA, benzenesulfonic, phenolsulfonic, and xylenesulfonic acids (among many other things, mostly phenol-formaldehyde and epoxy resins), and I must say that watching this video makes understanding the entire process much easier to understand than having the plant operators attempt to explain it to me. Very thorough and well explained...thanks!
how the hell does it form a monohydrate if water decomposes it back to toluene and sulfuric acid? is it just at higher temperatures that that happens?
The equilibrium requires strong acid to catalyze the reaction. Absent the catalyst, nothing happens.
It's the common ion effect. p-Toluenesulfonic acid (TsOH) in water exists in equilibrium with the deprotonated p-toluenesulfonate (TsO-) and hydronium. TsOH + H2O ⇌ TsO- + H3O+ According to Le'Chatelier's Principle, if the amount of product increases (caused here by adding HCl), the equilibrium will go to the left. As to why tosyl chloride isn't produced, I'll leave that question to someone more knowledgeable with organic chemistry.
what does the HCl do with the acid? I guess it protonates it, but wouldn't that INCREASE the solubility, because it gets more polar? And why don't you get TsCl then? Great video again, keep it comming :)
TsCl doesn't form, because the sulfonic acid "hydroxyl" group isn't susceptible to the SN1 and SN2 substitutions that can convert alcohols to alkyl chlorides. This is the same reason that HCl and acetic acid doesn't give acetyl chloride. You need to resort to something like thionyl chloride to convert TsOH to TsCl.
About the only use i have for this is the isomerization of CBD to THC in a cannabis oil preparation. AS it can be done with other more common acids ive never tried this...Hmmmm!
+TheZacdes bro i would not try this , i use to study explosives and from what i can tell you may be making T.N.T in this process . "trinitrotoluene" . i mentioned this to the guy doing this and his response was "FUCK OFF ABOUT THE HASH BRO" ... to make tnt you nitrate toluene and that is done with acids , nitric and sulfuric but who knows man , i wouldnt be surprised if this is a clasic example of a you tube know it all playn with shit he has no real concept of
@NOBOX7
I would not bother with this rather esoteric acid as other more common ones work perfectly for my purposes.:)
@NOBOX7 Nitric acid is absolutely the most critical part of making trinitrotoluene, it provides all the nitrogen. There's no nitrogen in toluene or sulfuric acid, so this reaction could not possibly produce TNT. Making TNT is actually really difficult, especially to do on accident.you need oleum (which he mentions in the video as a sulfonating agent, and is very difficult to get hold of and reacts violently with water) and anhydrous nitric acid. The synthesis also requires multiple steps (I assume to prevent sulfonating from occouring rather than nitration)
I don't know why I'm responding. Oh well.
Will this reaction still proceed if I replace the Barrett trap with a suitable quantity of anhydrous cupric sulfate? Thank You.
cool now i can make the best hash oil in town, ISOMERAZATION , and just have to say i love that you did this at 5AM
+NOBOX7 You dont need this acid for isomerization man, sulphuric and hydrochloric can be used with different solvent!!
They are rather technical for the average youtube viewer. I am comfortable with over 1000 subscribers and almost 100k views. Of course, analytics reveals that the average viewer stops watching after a few minutes and even those who watch the rest of the video bail on the mechanism, which I would consider one of the more valuable parts of the whole thing. Nonetheless, I know I have my niche little target audience of dedicated viewers and am comfortable there.
mechanism of the reaction here is shown WRONG!
hello sir Thanks for sharing your wisdom , please forgive the nature of my comment, im not a drug addict who condones drugs , but very important point here what are the dangers of producing trinitrotoluene "TNT" in this process, i do not want explosive salts in my hash bro
thanks in advance for your time
Fuck off about the hash, bro.
@MrItsthething thanks
If you don't have even traces of nitric acid in your reaction mixture, how do you expect to make TNT?
Ricardo Fernández-Terán xd
UC235 - 2012-10-22
Yes. I greatly enjoy what I do, even though it's a tremendous money pit.