Sciencemadness Discussion Board

p-toluenesulfonic acid synthesise problem

Brominator - 25-3-2013 at 11:13

I have attempted to synthesise p-toluenesulfonic acid,
to do so i refluxed methyl benzene and conc. sulphuric acid for 2 hours until most of the methyl benzene had reacted ,
but then on the work up appon addition of water some crystals came out of solution ( hopefully the mono hydrate of my product) but quickly redissolved so my question is how do i get my product back out of solution ?

Mercedesbenzene - 25-3-2013 at 15:41

p-toluenesulfonic acid is highly soluble in water. What you need to do and the procedure I have used from vogel's is to saturate the solution with hydrogen chloride. This should precipitate your product., Then collect by filtration and dry in a dessicator for a while.

Sublimatus - 25-3-2013 at 16:22

Mercedesbenz is correct.

Use Google to search the forum. I can recall answering threads about this subject before.