Gassing Toluene

[boilingchip]

SWIM used 100ml of Toluene to extract his pfed. After shaking he poured it into a sep funnel and let it set for a bit to allow the two layers to fully separate. He then poured off the toluene layer and gassed it with anhydrous HCL. Instead of any crystals forming, the toluene turned pink. SWIM is supposed to gas the toluene layer and not the water layer right? Any ideas as to what happened? In order to extract the pfed from the pills SWIM used Uncle Fester's Steam Extraction Method. To the resulting liquid is what SWIM added his toluene to. There is a lot written on extraction but haven't seen this pink problem before.

[Glasya]

Did you remember to dry the toluene before you gassed it?

[boilingchip]

The toluene was supposed to be bubbled with the gas. Not sure how to bubble something that is dry.

[Novice]

Dry in this context means that there is no water present. If you didn't dry the toluene extract (with for instance MgSO₄, Na₂SO₄ or some other drying agent) before gassing with HCl(g) there is a good chance you have wee amounts of water dissolved in it, which will fuck up the formation of crystals when gassing.

[Glasya]

There can't be any water in the toluene when you gas it our your product will "oil out", it will move into the little bit of water that is there. You need to add some MgSO4 to the toluene first, give it a few stirs and let it sit for awhile, then filter the toluene and then gas it (This will remove all the water prior to gassing).

If it has oiled out you need to do another A/B to get your product back. (You have already made it acidic, add a little more hcl and water to separate it, wash with toluene and the add base, extract with toluene, dry with MgSO4 and gas again.)

Not sure why it's pink, probably due to some impurity.

(I have been really nice, you should now UTFSE.)

[Novice]

Use the search engine, search for "over gassing", and you'll get lots of info on how to recover your product. Even though this is not a clinical example of over gassing, the procedure for recovery of an over gassed product will probably apply here as well IMHO.

[Stonium]

The toluene was supposed to be bubbled with the gas. Not sure how to bubble something that is dry.
When the glass rod or tubing or whatever outlet the gas is flowing from is inserted into the solvent that has been collected, "bubbling" will occur. Exerting pressure on whatever container the gas is housed in will increase the bubbling. This "bubbling" is  quite evident to one's eyes and ears. If you didn't notice this during the gassing process, I really have to wonder if you ever actually gassed it in the first place.  

[boilingchip]

I appreciate everyone's help. I was mainly wondering why it turned pink and after UTFSE for quite some time and not seeing any reference to 'pink', I asked the question. Also, since I'm a newbee I put it in that forum. I did not know about using the magnesium sulfate as Uncle Fester didn't mention that in the instructions I read, so thanks for clarifying that! Cheers.

[Novice]

The pink color comes when the pH of the solution drops to <1, which it does because of the water present, as pH=-log[H₃O⁺].

Upon further gassing, the product (if it precipitates) or solution turns red, which figures since pink is a nuance of red.

Use the search engine and enter Stanley as username and "isolation" as subject, enter the thread and read up on the posts there...