Sciencemadness Discussion Board

Reduction Of Salicylic Acid To Benzene

Jmap science - 13-12-2013 at 19:33

I read that Phenol can be reduced by distilling it with zinc dust. This yields benzene and zinc oxide. The advantage of this is that you don't need much to do it.

I don't have phenol but I do have salicylic acid. Could I first distill with calcium oxide to make phenol and then distill with magnesium dust instead of zinc to make benzene. I have lots of aspirin tablets in my lab!

Making salicylic acid is easy but I would like more of a challenge. As always excuse my lack of knowledge in organic chemistry and thanks for the help.

[Edited on 14-12-2013 by Jmap science]

bfesser - 13-12-2013 at 19:50

Quote: Originally posted by Jmap science  
The advantage of this is that you don't need much to do it?
That's not even a question.

Jmap science - 13-12-2013 at 20:52

lol sorry, my mistake.

Paddywhacker - 14-12-2013 at 01:52

What you propose is plausible enough for you to make the attempt, assuming you have the reagents to spare. I would advise reading up about other methods of making benzene. As a flammable liquid it is as dangerous as gasoline, so take care.

As well as the flammability problem, phenol is quite dangerous. It melts at a low temperature and also turns liquid with only 10% water. The liquid is fat soluble, so it will sink right into your skin. It is also cytotoxic, killing any skin cells that if gets onto. The result is a nasty deep hole in your flesh. But that is only with a big dollop of the stuff.

vmelkon - 19-12-2013 at 18:31

Maybe this will help
============================
A chemistry book on google (Kings Chem Guide by Jared Ledgard
http://books.google.ca/books?id=y5mZrW1KB_AC&pg=PA129&am...

says that you can heat salcyclic acid directly and it breaks down to phenol and CO2.
Similar to aspirin, salicyclic acid is unstable towards heat. It breaks down.
Place some in a glass apparatus. About 25 g. Heat for 5 to 6 seconds at a time. Pause for 10 to 15 seconds. Heat with a bunsen burner. Repeat the process for 10 to 15 minutes.
Stop and let it cool.
Add 100 mL of methylene chloride (DCM, CH2Cl2) and swirl to dissolve the phenol.
The place the CH2Cl2 in a distillation apparutus and boil it (bp = 39.6 °C for CH2Cl2).
You will have phenol at the bottom, 95 to 98% pure.

Mr_Magnesium - 20-12-2013 at 07:12

http://www.sciencemadness.org/talk/viewthread.php?tid=27617

A very nice write up which is a nice read,

thermal decarboxylation of salicylic acid to phenol

magnesium could work as well

[Edited on 20-12-2013 by Mr_Magnesium]

Benzoic Acid from Salicylic acid

soniccd123 - 30-12-2015 at 22:25

I also have read that distilling Phenol with Zinc powder yelds Benzene; i would like to know if distilling Salicylic Acid with Zinc powder could yeld Benzoic Acid. I'm willing to try it, but want to know if this sounds alright before doing it.

macckone - 31-12-2015 at 00:23

Quote: Originally posted by soniccd123  
I also have read that distilling Phenol with Zinc powder yelds Benzene; i would like to know if distilling Salicylic Acid with Zinc powder could yeld Benzoic Acid. I'm willing to try it, but want to know if this sounds alright before doing it.

No, zinc will reduce benzoic acid with decarboxylation. You will have a mix of benzene toluene and various biphenyls.

CuReUS - 31-12-2015 at 00:43

Quote: Originally posted by Jmap science  
I read that Phenol can be reduced by distilling it with zinc dust. This yields benzene and zinc oxide. The advantage of this is that you don't need much to do it.

what you haven't read is that there is no experimental data(that I could find atleast) for this reaction,although it is given in many orchem books.you might be the first person in modern times to actually try it. good luck;)