Quote: Originally posted by axd1995  | I used 20ml of 92% sulfuric acid and 3.6g of salicylic acid. After heating, I added salicylic acid, but it couldn't completely dissolve. I raised the
heating temperature and there was a strong phenol odor, but it still couldn't completely dissolve. Why? |
I would suggest using Rosco's picric acid method. The only thing is that you need more nitrate salt than for using ASA. But since you're using
salicylic acid (which in my own opinion, is superior to ASA in every way, I think my picric acid was ultra pure even without a recrystalization when I
made it with salicylic acid).
I would suggest using more sulfuric acid. I use 95+% sulfuric acid (I clean drain cleaner grade with H2O2 and then boil it for 95 minutes or so). Like
4ml for every gram of salicylic acid. this is a great excess, but I was able to fully dissolve all of my salicylic acid in H2SO4 before I even began
the heating step, so I know it is an excess, but it will guarantee that you will be able to make it work.
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