How to make the pyridine dry? Preferably with NaOH drying agent. I want the detailed procedure
If we need to get every single water molecule out of pyridine, then the final stage of drying (after treatment with molecular sieves or calcium hydride) should be with potassium metal. We can tell when the last water molecule has been destroyed because the remaining potassium metal deprotonates some of the pyridines. This makes a deep red precipitate, which acts as an indicator to show that it is completely dry. So, the best way to do this is to reflux the pyridine over potassium metal (which will melt) in a sealed schlenk-bomb with a greaseless Teflon valve. Ideally having freeze-thaw degassed it first so that it refluxes in only its own vapor pressure. Then vacuum transfer it to a clean, fresh schlenk-bomb containing some properly activated (heated under a vacuum) molecular sieves.
https://www.reddit.com/r/chemistry/comments/5gb7pm/drying_pyridine/
Pyridine is hygroscopic and is miscible with H2O and organic solvents. It can be dried with solid KOH, NaOH, CaO, BaO or sodium, followed by fractional distn. Other methods of drying include standing with Linde type 4A molecular sieves, CaH2 or LiAlH4, azeotropic distn of the H2O with toluene or benzene, or treated with phenylmagnesium bromide in ether, followed by evaporation of the ether and distn of the pyridine. (Look chem Website)
Mam, you can get your answer. Here is the link--
https://www.lookchem.com/Chempedia/Chemical-Technology/Laboratory-Chemical-Technology/13955.html
Sir, you can get your answer the below link-
(https://www.lookchem.com/Chempedia/Chemical-Technology/Laboratory-Chemical-Technology/13955.html)
I have the same question. I have read many times the methods to dry pyridine. But now I want a standard procedure with precautions. But no one has replied on this point.
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