Justanovice
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How can I extract my product from pyridine?
I'm trying to make 2-tosylethanol from ethylene glycol and ethylene di-tosylate. I followed a paper, but they don't discuss the work-up. The reaction
was neat, so I'm not certain how to get my product out of the pyridine. Heat obviously degrades my tosylethanol, so I'm trying to determine the best
solvent to extract my product from the pyridine without bringing the pyridine with it. Any suggestions?
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Justanovice
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Correction: my apologies, I'm not using ethylene glycol + ethylene di-tosylate. I meant to write ethylene glycol + tosylchloride.
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Satan
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Post references.
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Justanovice
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Jerald S. Bradshaw, Krzysztof E. Krakowiak, Gypzy C. LindH
and Reed H. Izatt. Tetrahedron.. 43 *1987) pp. 4271.
"...The solid was filtered and the solvents were evaporated under reduced pressure. The resulting oil was chromatographed on silica
gel using 2%1 ethanol in methylene chloride as eluent."
But, there's no mention of the solvents they used to extract the product. They also said;
"This material was prepared in a manner similar to that reported by Nitta and Arakawa (Y. Nitta and Y. Arakawa Chem. Pharm.
Bull., 33 (1985), p. 1380.)"
However, I don't have access to that reference so I'm not certain what Nitta did.
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DJF90
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Your solvent is the pyridine...
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Nicodem
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You can just rotavap (don't heat the bath!) the whole reaction mixture, dissolve in the minimum amount of the eluent, filter from the Py.HCl and put
on the column. Whatever you do, just keep the glycol monotosylate or its solutions away from anything more basic than pyridine, as it will rapidly
cyclize to ethylene oxide just like 2-bromo- and 2-chloroethanols do. Also, threat it as a highly probable carcinogen, just like you would treat the
2-haloethanols or their active form ethylene oxide.
Why do you need this compound for? It is pretty useless for alkylations of basic nucleophiles as there are better reagents for in situ ethylene oxide
formation from already commercially available reagents. For non-basic nucleophiles you can always use 2-bromoethanol and if it this not reactive
enough you can apply iodide nucleophilic catalysis.
If instead you want to modify the remaining hydroxy group, you might consider changing the synthetic sequence as it might be much better in regard to
selectivity, yield and safety.
Quote: Originally posted by Justanovice  | "This material was prepared in a manner similar to that reported by Nitta and Arakawa (Y. Nitta and Y. Arakawa Chem. Pharm.
Bull., 33 (1985), p. 1380.)"
However, I don't have access to that reference so I'm not certain what Nitta did. |
Chem. Pharm. Bull. is a free access journal, so you will have a hard time convincing us that you don't have access to that article. That article was mentioned in a forum thread on tosylation of alcohols and in another one on tosylic acid.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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