Sciencemadness Discussion Board

OTC Dimethyl Ether

Hawkguy - 16-5-2015 at 19:30

I don't know if this is covered already, but it turns out Dimethyl Ether is sold in grocery stores/ pharmacies for the removal of warts. It seems pure, but the price isn't great. A little bottle costs just over $20...

blargish - 16-5-2015 at 19:44

Wikipedia states that a mixture of dimethyl ether and propane is commonly used to freeze warts (since it is a gas at room temp). So I assume that the bottle you found it in has a spray nozzle?

Hawkguy - 16-5-2015 at 22:27

Yes, about 30ml in a small bottle with a spray nozzle. When I checked the packaging, it only said it contained Dimethyl Ether, so I assumed I just found a pretty chill Methylating agent for future reference.


diddi - 17-5-2015 at 02:49

I would still go for automotive starter fluid which is generally quite good value for money.
eg (for .au)
http://www.supercheapauto.com.au/online-store/products/CRC-A...

MSDS states 10-30% diethyl ether so about 100grams for 15$

BromicAcid - 17-5-2015 at 05:15

For what it's worth diddi, the original poster was talking about di<b>methyl</b> ether, not di<b>ethyl</b> ether. Although I don't see diemethylether from as being very useful to a home chemist, it is an interesting tidbit of knowledge that it is in an over the counter product.

woelen - 6-1-2020 at 04:30

At the moment you can buy this material in pure form as an extraction agent for oils from all kinds of plants. It is sold on eBay, but also by many other webshops online, at least in the EU. I purchased a gas cylinder of this, with appr. 500 ml of the gas in liquid form. Just search eBay for "DME" or "dimethyl ether". It is much cheaper than the prices, mentioned in this thread in earlier posts.

I did an interesting experiment with dimethyl ether, in making a solution of an oxonium salt. Dimethyl ether dissolves very well in conc. H2SO4 (1 ml of H2SO4 certainly dissolves 100 ml of the pure gas and above the resulting liquid there isn't any vapor pressure). I took 5 ml or so of H2SO4 and all together I think I have dissolved appr. half a liter of the gas in this 5 ml of acid. The volume of the liquid increases considerably and also quite some heat is produced when the gas dissolves in the acid. I used a small bottle with the acid in it and let the bottle fill with gas and waited till most of it is absorbed (swirling around the liquid somewhat) and then let is cool down again before letting air in (underpressure!). After three rounds of letting air in, I added the next amount of gas and repeated this a few times, until absorption of the gas becomes slower.

This liquid I obtained is an ionic liquid, conducting electricity quite well. The compound forms ions:

H3C-O-CH3 + H2SO4 ---> H3C-O(H+)-CH3 + HSO4(-)

So, you get a solution of dimethyloxonium bisulfate in H2SO4.

Dimethyl ether resembles dimethylamine somewhat, which forms dimethylammonium ions. Dimethylammonium ions, however, are more stable than dimethyloxonium ions.
I also tried diluting the dimethyloxonium bisulfate in water, but that does not work. As soon as the liquid comes in contact with water, it sinks to the bottom and most of the dimethyl ether is released as gas. This is accompanied with a fairly loud hissing/bubbling sound. Remarkably little heat is produced in mixing this liquid with water (much less so than mixing conc. H2SO4 with water). The final liquid, however, just is dilute H2SO4 probably with a little dimethyl ether dissolved as well. I do not think that in water there still is an appreciable amount of the oxonium ion present.

I'll keep around some of this solution. Let's see how stable it is and in the meantime I will look for experiments which I can do with this oxonium ion. It really is a pity that it is not stable in water, this limits its usefulness in experimenting.

Pumukli - 6-1-2020 at 11:31

"found a pretty chill Methylating agent for future reference"

Really? What can be methylated by DME?

woelen - 6-1-2020 at 14:16

DME is not a strong methylating agent, it actually is fairly inert at room temperature. At elevated temperatures of a few hundreds C, however, it is very reactive. This also makes it extremely flammable.
I intend to use it for solution chemistry experiments.

Btw, if you are in the EU, this may be interesting for you: https://420shop.nl/dexso-gas.html

Here I purchased the gas.