Sciencemadness Discussion Board

Oxime reaction. Solvent substitutions?

lancer3000 - 22-9-2011 at 17:39

In the formation of oxime, can Methanol be substituted for the solvent, instead of Ethanol?

I have heard both side of the story, where Methanol can change the outcome of the reaction... and the other side is a solvent is a solvent, and methanol will react exactly the same as ethanol...

Thoughts?

Thanks.

AndersHoveland - 22-9-2011 at 18:19

I do not see any reason why methanol would be any different than ethanol as a solvent in this situation.
But I prefer to use ethanol, since it is not nearly as poisonous as methanol.

lancer3000 - 23-9-2011 at 09:28

Hi Anders.

Thanks for the response. This is good to know.

I dont like all the dangers with methanol either, but as long as proper precautions are taken it shouldnt be very dangerous, i.e. full and thorough evaporation...

I have another questions, which may need nee thread but would rather not flood the boards.

Can another solvent be used in place of methylene chloride? It is very popular for washes an extractions, perhaps due to its polar nature. Its not a problem of buying it, the price is just so much higher than any other solvent! If the main solvent was methanol/ethanol, and dcm is normally used, what can a substitution be for dcm?

Thanks again.

AndersHoveland - 23-9-2011 at 09:45

Methylene chloride solvent-based products can commonly be obtained as "model airplane glue", or in several automotive cleaning solvents.

In many cases, chloroform can substitute for methylene chloride. Not sure if simple oximes typically dissolve in chloroform, but I did found a paper saying that this oxime molecule is soluble in chloroform:
C6H5-CH(OH)-C(=NOH)-C6H5

Interestingly, many health food stores actually sell DMSO. It is pharmaceutical grade, and so is unfortunately typically very expensive.

[Edited on 23-9-2011 by AndersHoveland]

barley81 - 23-9-2011 at 09:47

You can distill methylene chloride from BBQ cleaner or certain types of paint stripper (Jasco). It will have some methanol in it though. Look on youtube for videos describing the process. Also, the price isn't that high. Elementalscientific.net sells it for about $8 per pint.

lancer3000 - 23-9-2011 at 10:38

I was hearing 45-50 a gallon, compared to almost all other solvents, in the 10-25 range...