Sciencemadness Discussion Board

Aspirin to picric acid apparatus

Hunterman2244 - 16-8-2018 at 03:59

So far this is a draft, but due to the boiling point of phenyl acetate and its wide liquid range, this method seems very favorable.

Aspirin and NaOH/KOH are put into a flask and heated. The aspirin decarboxylates into phenyl acetate, which decomposes whith NaOH or KOH to leave phenol and an acetate salt. The phenol boils off and is distilled into a nitration mixture on an ice bath. The mixture containsvnitric and sulfuric acid, or simply a nitrate salt dissolved in sulfuric acid which is easier for the amateur chemist to prepare.


[Edited on 16-8-2018 by Hunterman2244]

Sigmatropic - 16-8-2018 at 08:21

I thought the more common sequence going through phenol is hydrolysis of asprin (under acidic conditions, or in under basic conditions followed by acidic work up) to give salicylic acid which is then dry distilled to give crude phenol. Redistillation gives pure phenol. This is then subjected to nitration.

Alternatively I belive asprin can be directly converted to acetyl picrate which is so hydrolytically labile that aqueous work up affords picric acid. The crude picric acid is then recrystalized from ethanol or hydrochloric acid or ethanol containing hydrochloric acid.

Look for experimental procedures from published articles, there is no use trying to reinvent the wheel. Amateur chemistry is already hard enough.

Hunterman2244 - 16-8-2018 at 11:12

Quote: Originally posted by Sigmatropic  
I thought the more common sequence going through phenol is hydrolysis of asprin (under acidic conditions, or in under basic conditions followed by acidic work up) to give salicylic acid which is then dry distilled to give crude phenol. Redistillation gives pure phenol. This is then subjected to nitration.

Alternatively I belive asprin can be directly converted to acetyl picrate which is so hydrolytically labile that aqueous work up affords picric acid. The crude picric acid is then recrystalized from ethanol or hydrochloric acid or ethanol containing hydrochloric acid.

Look for experimental procedures from published articles, there is no use trying to reinvent the wheel. Amateur chemistry is already hard enough.

I know of the usual way, my point was to challenge myself to find a different one. The way I chose to do it was to simplify the procedure. There are different ways to do things, my way is simply to build an efficient way of doing it with minimal involvement. Your idea seems interesting and would be nice of it works, I simply decided to come up with my own.