Sciencemadness Discussion Board

Help !! Methyl Salycilate

kuldesak - 21-12-2005 at 09:04

Anybody can help me ?
I have problem to design methyl salycilate plant.
i make methyl salycilate from methanol and salycilic acid
what reactor must be used ? CSTR/fixed bed ?
If you have flow diagram of methyl salycilate pls send to me
Thanks

Darkblade48 - 21-12-2005 at 12:49

Check the prepublication section of these forums, I posted a synthesis of methyl salicyliate there.

Though why you would want to make a "plant" is beyond me. If you really need it in large scale amounts, you can always go to a pharmacist and pick up some.

garage chemist - 21-12-2005 at 15:12

It seems like this is an engineering question.

Methyl salicylate would probably best be made in a batch reactor, from salicylic acid, a five- fold excess of methanol (gets distilled off and recycled later) and HCl gas (dissolved in the reaction mix, easier to remove than H2SO4) as catalyst.
Reaction would consist in refluxing for some time and then distilling off methanol, HCl and byproduct water and then fractionally distilling the methyl salicylate from the salicylic acid, perhaps in vacuum. This way the methanol and unreacted salicylic acid are recycled. Methanol and water will be separated by fractional distillation.
This way no water would be needed for H2SO4 removal and thus no chemically contaminated waste water produced, which is a big advantage with todays environmental regulations.

I made up this process right now, without knowing how methyl salicylate is actually produced industrially. It would be nice if someone could post the actual process so that I can see how close I am.

pyrochem - 29-1-2006 at 08:36

Methyl salicylate is found in wintergreen plants. It is sold in pharmacies as oil of wintergreen, but this might be impure. It seems that it is made industrially from the esterification of methanol and salicylic acid.