Sciencemadness Discussion Board

Zylenesulfonic Acid

TheChemiKid - 8-3-2014 at 06:12

I was very interested in making Xylenesulfonic Acid, and after some thinking, I believe it could be made by removing water by a dean stark trap while refluxing xylene and sulfuric acid.
I do not have a dean stark trap, but I know in the synthesis of p-Toluenesulfonic Acid, water can be distilled off instead of being removed by a dean stark trap. I would think the same could be done with Xylenesulfonic Acid.
Has anyone attempted this synthesis, or will I be the first (that we know of)?

[Edited on 3-9-2014 by TheChemiKid]

thesmug - 8-3-2014 at 09:05

I think you're pretty spot on but do you have access to sulfur trioxide? If so, that would be the easier way of sulfonating your xylene.

TheChemiKid - 8-3-2014 at 12:38

No, unfortunately I don't. I could make a generator with a sulfate decomposing though. I think sulfuric acid would be easier, even if there is a lower yield.

Metacelsus - 8-3-2014 at 13:29

Quote: Originally posted by TheChemiKid  
refluxing toluene and sulfuric acid.


Don't you mean xylene?

Is your xylene a mixture of isomers, or just one isomer?

Tsjerk - 8-3-2014 at 14:08

Are you aiming for the mono- or disulfonic acid?

Oscilllator - 8-3-2014 at 14:29

You can improvise a dean-stark trap (as shown in the picture). It worked quite well for my synth of p-toluenesulphonic acid.

IMG_20140221_150501.jpg - 393kB

subsecret - 8-3-2014 at 18:19

That's an interesting apparatus to replace a Dean-Stark trap, Oscillatior. I've thought about making a similar one, but using a two-necked flask and a reflux condenser in place of the "stillhead."

Very interesting.

TheChemiKid - 8-3-2014 at 20:59

Quote: Originally posted by Cheddite Cheese  
Quote: Originally posted by TheChemiKid  
refluxing toluene and sulfuric acid.


Don't you mean xylene?

Is your xylene a mixture of isomers, or just one isomer?

Yes, stupid me. I fixed the mistake.
Quote: Originally posted by Tsjerk  
Are you aiming for the mono- or disulfonic acid?

I was originally aiming for the mono-, but I could try to make the di- as well.

Paddywhacker - 8-3-2014 at 23:13

Have you looked up the sulfonation of xylene?

I think you will change your plans completely when you do.

TheChemiKid - 9-3-2014 at 05:14

I looked it up. I am not sure what you mean when you say I "will change my plans completely when I do."

Can you please elaborate?

Paddywhacker - 10-3-2014 at 16:16

Quote: Originally posted by TheChemiKid  
I looked it up. I am not sure what you mean when you say I "will change my plans completely when I do."

Can you please elaborate?


You looked it up where?

Have you ever seen Dean Stark apparatus used for this reaction?

Have a look at the preparation of toluene sulfonic acid and then the relative reactivities of benzene, toluene and xylene. Do you really think you need the conditions that you propose?

TheChemiKid - 10-3-2014 at 16:31

Have you seen Unintentional Chaos' prep?

Hockeydemon - 11-3-2014 at 01:22

Quote: Originally posted by Oscilllator  
You can improvise a dean-stark trap (as shown in the picture). It worked quite well for my synth of p-toluenesulphonic acid.


Brilliant idea thank you. It never occurred to me to use my claisen adapter as a dean stark.

TheChemiKid - 11-3-2014 at 07:30

For me, buying a dean stark trap costs 5 dollars more than a claisen adapter, so I am going to buy a dean stark trap.

Paddywhacker - 11-3-2014 at 18:22

Quote: Originally posted by TheChemiKid  
Have you seen Unintentional Chaos' prep?

Have you looked at Vogel? Vogel's main prep, on page 874 simply reacts the two reagents. The reaction is not an equilibrium, so removing the water azeotropically by Dean Stark is an unnecessary complication.

UC does write the reaction as an equilibrium in his video, but that is incorrect. These sulfonic acids are quite stable and not subject to hydrolysis. Were that the case then a DS trap would make sense, but it is not.

TheChemiKid - 12-3-2014 at 07:25

Is that in Vogel's third or fifth edition?

Mailinmypocket - 12-3-2014 at 07:47

Third, in the forum library. Although the fifth likely has it as well. I did it exactly as per vogels third without a Dean-Stark trap and it went well :)

TheChemiKid - 12-3-2014 at 13:22

Thank you.

Paddywhacker - 12-3-2014 at 14:09

Quote: Originally posted by Mailinmypocket  
Third, in the forum library. Although the fifth likely has it as well. I did it exactly as per vogels third without a Dean-Stark trap and it went well :)


Right, and with xylene the reaction will go at even milder conditions.

However, that being said, if you want to purify the product by short-path vacuum distillation then you'll have to remove the water, and doing so azeotropically by Dean Stark is probably as good a method as any.