Sciencemadness Discussion Board

2-methyl-3-butyn-2-ol

Mercedesbenzene - 26-11-2012 at 21:05

I am looking into preparing 2-methyl-3-butyn-2-ol or dimethylethynylcarbinol. I want to attempt to synthesize this from calcium carbide, potassium hydroxide and acetone as by Kazarian in 1934. I found the reference to his article from the organic synthesis article dimethylethynylcarbinol. However, I have not been able to find the article yet, only references to it. I was wondering if anyone else had any experience in preparing this compound or has this article. I am planning to finely powder the calcium carbide and potassium hydroxide and mix them in an equal molar quantity then suspend the particles in an inert solvent and slowly add acetone. Then workup the product by quenching, extracting then distilling the product. I found a very basic reaction mechanism here:
http://archive.org/details/organicsemi38391univ on page 80.
Anyone have thoughts on this reaction and reaction conditions?

[Edited on 27-11-2012 by Mercedesbenzene]

Lambda-Eyde - 26-11-2012 at 21:34

The article you're referring to appears in J. Gen. Chem. U.S.S.R., so it is most likely (>99%) in Russian. If you still think it could be of use to you I could do a SciFinder search (provided you haven't done so yourself) later today.

Mercedesbenzene - 26-11-2012 at 21:46

I haven't yet done a Scifinder search. I might be able to get some useful information out of the article from a) google translate or b) someone who speaks russian. If it indeed is in russian

ScienceSquirrel - 27-11-2012 at 05:55

I am not sure that your synthesis of ethynyl potassium would work, there is a preparation of it here;

http://link.springer.com/article/10.1007%2FBF01083799?LI=tru...

Mercedesbenzene - 27-11-2012 at 09:47

Hm. Thats true. However, I have the reagents so I will be trying to see if it works when exams are done in two weeks from now. I will let you guys know if it works or not. If not I might go the lithium or sodium acetylide route as there are many available procedues out there.

DJF90 - 27-11-2012 at 10:01

Acetylenes can be deprotonated using KOH/MeOH. I dont know how acetylene itself will hold up; I suspect you'll only get the monoanion but this is what you want! I can vouch for this working with Phenylacetylene.

ScienceSquirrel - 28-11-2012 at 04:08

You could try adding calcium carbide to a solution of potassium hydroxide in methanol and then adding acetone.

Nicodem - 28-11-2012 at 07:53

The simplest methods rely on the addition of acetylene on acetone in DMSO using KOH as the catalyst (KOH in DMSO is more basic than the monopotassium acetylide). See DOI: 10.1007/s11178-005-0331-7 for an example. See also DOI: 10.1002/jlac.198219820916 for another method using PTC conditions with 15% NaOH(aq) and toluene.
Quote: Originally posted by Lambda-Eyde  
The article you're referring to appears in J. Gen. Chem. U.S.S.R., so it is most likely (>99%) in Russian.

That journal has an English translated version that runs in parallel to the Russian one (but I did not check if the English translation goes as far back as 1934). It is a common journal, so it should not be difficult to find it in the libraries or via interlibrary exchange (or via References request). If one can't find the original article, the reactions applying the direct use of calcium carbide are reviewed in DOI: 10.1021/cr60065a006.

Mercedesbenzene - 1-12-2012 at 12:00

That's a very interesting paper Nicodem. I will most try this method next. I tried the calcium carbide, potassium hydroxide and acetone method. I suspended fine powders of calcium carbide and potassium hydroxide in a some ether. I heated the mixture and nothing happened. I added the acetone and left to reflux while I had dinner. I came back to find that the colour had changed from brown to green and the mixture had become very thick. I worked up the mixture. There was a strong metallic garlic smell present after quenching with water. I presumed this to be phosphine and other noxious impurities so this step was done in the fumehood. After extracting the aqeuous layer with ether I dried and filtered the resulting solution which was green in colour. I didn't have time to purify it so that will be done next week. I plan to remove the ether on a water bath and purify the resulting liquid by column chromatography as the amount of obtained produced is expected to be small. I worked on a 0.1 molar scale. I hope the KOH and DMSO method works better as I don't fancy working with phosphine which results from impure calcium carbide.

Lambda-Eyde - 6-12-2012 at 01:06

Quote: Originally posted by Lambda-Eyde  
If you still think it could be of use to you I could do a SciFinder search (provided you haven't done so yourself) later today.

"Later" and "today" are both relative terms, right?

The SciFinder search didn't turn up anything, and I can't find it anywhere else, so I guess it hasn't been digitalized. I asked at the university library, but they didn't have any volumes from earlier than 1949. I'll see if I can track it down somewhere else and order a digital copy of the article.

Edit: Oh, and the conversation with the (young and new) clerk at the library was pretty funny:

Me: Hey
Her: Hi, can I help you?
Me: Um, yeah... I'm looking for... The Soviet Journal of General Chemistry?
Her: Okay, let's see here... Hm, which volume?
Me: Fourteen.
Her: Mhm. And what year?
Me: ... 1934
Her: Right.
Me: Right.
Her: You know, I don't think it's looking good for you...
Me: You don't say...

I doubt she gets such obscure requests every day. :D

[Edited on 6-12-2012 by Lambda-Eyde]