Author Topic: p-toluenesulfonic acid  (Read 19006 times)

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  • Guest
« Reply #40 on: August 05, 2002, 12:25:00 PM »
The contents of the flask have turned black and it looks like there's some crap "baked" to the inside of the flask. I hope I can clean the flask out OK.. I'll run it until the cloudy toluene settles in the dean stark, then see...

The dean stark trap made all the difference, it allowed the tosic acid to go into the toluene instead of staying dissolved in the small amount of water! Excellent! This stuff looks pretty nasty, but hopefully it's just a small amount of impurities... time to go prepare some isosafrole glycol.

P.S. I think if I was going to run batch after batch of the rearrangement I'd prepare a bunch of tosic acid in toluene at once, then use a bit of the solution at a time.


  • Guest
maybee this might help,
« Reply #41 on: August 07, 2002, 04:08:00 AM »
I have skimmed through your posts, and have realized there seems to be a simple component missing to your preperation of p-toluenesulphonic acid, Why are you not using HCL,

Here it is how it should read,.


In a round bottom flask (50ml) fitted with a reflux condensor place pure toluene (13g, 15ml) and conc. sulphuric acid (11g, 6ml).
Boil the mixture gently for 5 minutes with frequent shaking to mix the layers.  Cool the mixture in ice water and decant and discard the upper layer (principally toluene); add conc hydrochloric acid (12ml), attach the condensor, heat gently ,just as long as necessary to obtain a clear solution and then cool, as before.
The solid that precipetates is mainly the p-acid but is contaminated with the o-isomer; filter it at the pump and repeat the crystalization to obtain the p-isomer (3-3.2 g) mp.103-105.
If the acid is still slightly deliquesent, repeat the crystallisation to obtain a pure sample, mp 105c.

If This is what you have been doing, forget this post.


IQ is the rate of logic, as Wisdom increases logic, fear & compromise decrease to reveal objectivity


  • Guest
Thank you
« Reply #42 on: August 07, 2002, 06:18:00 AM »
Thanks for the post, but I don't have conc HCl (just the whimpy 31%).

Making tosic acid in toluene has worked fine though as I posted (the dean stark is necessary!). The flask was easy to clean too. Some crystals have precipitated from the toluene over the last few days tho (odd?). Anyways, I'm just waiting for some peracetic acid to form, then I'll get on with the epoxidation, then rearrangement and let you all know.

Hopefully this means an increase in everyone's yields.  :)


  • Guest
You can most likely use 31% HCl, conc HCl is only ...
« Reply #43 on: August 07, 2002, 06:36:00 AM »
You can most likely use 31% HCl, conc HCl is only 5% stronger. Just adjust for the different concentration.


  • Guest
Conc HCl
« Reply #44 on: August 08, 2002, 10:04:00 PM »
Just gass the 31% HCl and make it concentrated, thats not too hard is it?

Those who give up essential liberties for temporary safety deserve neither liberty nor safety


  • Guest
I would walk a thousand miles
« Reply #45 on: August 10, 2002, 07:59:00 PM »
Just to see , duh,duh, duh, duh,
The rearrange done like this,
Eagerly awaiting the tosic acid rearrangement news,.

Im not a newbee- arrrrgggghhhhhhh

IQ is the rate of logic, as Wisdom increases logic, fear & compromise decrease to reveal objectivity ;)


  • Guest
Rearrangement news
« Reply #46 on: August 10, 2002, 08:29:00 PM »
Some detail is in

Post 344100

(Chromic: "OTC tosic acid rearrangement SUCCESS!", Methods Discourse)
. I've got the oxime in the freezer, it doesn't look like it has fully crystallized yet. Perhaps it won't. I'll vac filter tomorrow and let everyone know.


  • Guest
Need Translator & Complete Specification
« Reply #47 on: September 20, 2002, 02:38:00 AM »

A process for synthesizing p-cresol by direct alkali fusion of p-toluenesulfonic acid includes such technological steps as preparing p-toluenesulfonic acid by sulfonating reaction of toluene on sulfuric acid, direct alkali fusion of p-toluenesulfonic acid with fused sodium hydroxide to obtain cresol sodium, acidifying it with SO2 to obtain coarse cresol and then separating to obtain p-cresol. Itsadvantages include no need of neutralization step, less consumption of energy and raw materials, short reaction time reduced by 4/5, and high output rate increased by 10%.
  I found the above patent at

, but it's only the abstract. Anyone know where to find the complete specification? Peace! 8)

Love my country, fear my government.


  • Guest
Can you read chinese?
« Reply #48 on: September 20, 2002, 03:36:00 AM »
Can you read chinese?
Because if you don't that patent won't be of any use to you.

I'm not fat just horizontally disproportionate.


  • Guest
Ya know
« Reply #49 on: September 20, 2002, 01:28:00 PM »
There was an infrared pen I noticed at fryes electroncs the other day that you use to scan froiegn documents and it hooks up to the usb port in youtr computer.
It has a dictonary of 35 languages you download from thier website and it automatically translates whatever you scan.
Looks like one you bees with money should buy one for such uses, and offer a translating service to all of us.
BTW it costs $ 200.00


  • Guest
No, I can't read mandarin, smart ass .
« Reply #50 on: September 20, 2002, 04:01:00 PM »
No, I can't read mandarin, smart ass. I just thought I'd throw it out here just in case there's an english text article floating about somewhere, or maybe there are equivalents. I can't find any other patents that are geared specifically towards the production of p-tosic acid, just halogenated stuff.

  For whatever it’s worth, p-tosic acid’s soluble in DMSO

”Other suitable organosulfonic acids will be readily apparent to the skilled of the art. The most preferred organosulfonic acid is para-toluene sulfonic acid (p-TsOH), in view of its wide commercial availability, low cost, and high solubility in the sulfoxide solvents of the invention.”

UPDATE: Check this out;



  Peace! 8)

Love my country, fear my government.