Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
 Pages:  1  2    4
Author: Subject: Possible OTC, 'safe' methylating agents
itsafineday
Hazard to Self
**




Posts: 54
Registered: 5-1-2019
Member Is Offline


[*] posted on 14-2-2019 at 15:23


Doh! I am such and eeeeediot :) and good at wasting money in this hobby.
View user's profile View All Posts By User
TGSpecialist1
Harmless
*




Posts: 40
Registered: 24-12-2017
Member Is Offline

Mood: always tired

[*] posted on 17-2-2019 at 21:55


I wonder if it would be possible to make dimethyl carbonate by dissolving magnesium in methanol, bubbling dry CO2 through it to make magnesium methyl carbonate, distilling to dryness, then cracking it with heat to dimethyl carbonate and magnesium carbonate.
View user's profile View All Posts By User
clearly_not_atara
International Hazard
*****




Posts: 1563
Registered: 3-11-2013
Member Is Offline

Mood: No Mood

[*] posted on 21-2-2019 at 16:43


You know, I keep trying to think of a problem with that and I can't. It does seem like it would work better if you could obtain metallic calcium, just based on analogy to similar reactions, but Mg should be fine I guess.



[Edited on 04-20-1969 by clearly_not_atara]
View user's profile View All Posts By User
Chemi Pharma
National Hazard
****




Posts: 271
Registered: 5-5-2016
Location: Latin America
Member Is Offline

Mood: Resaler

[*] posted on 26-2-2019 at 11:13


I have a patent teaching how to produce (DMC) Dimeyhyl Carbonate without the use of Phosgen. They use just Dimethyl oxalate (easy to produce. See here at Doug's Lab You Tube vídeo: https://www.youtube.com/watch?v=imtSH3OAdKE) and Sodium Methoxide at 100ºC.

The Patent is attached:

Attachment: Dimethyl carbonate from dimethyl oxalate and sodium methoxide.pdf (269kB)
This file has been downloaded 64 times
View user's profile View All Posts By User
starlight_
Harmless
*




Posts: 18
Registered: 7-11-2018
Member Is Offline


[*] posted on 27-2-2019 at 12:08


That’s a very interesting post by Chemi Pharma on preparation of dimethyl carbonate.

Is an autoclave necessary to do this do you think, or could the DMC be distilled off as it is formed by heating up reactants in standard rbf? (Obviously CO would have to be vented or scrubbed).
View user's profile View All Posts By User
Chemi Pharma
National Hazard
****




Posts: 271
Registered: 5-5-2016
Location: Latin America
Member Is Offline

Mood: Resaler

[*] posted on 27-2-2019 at 20:12


The Patent say that the temperature of the batch needs to stay between 50-150ºC. cause this I think an autoclave use is not mandatory. I'd rather heat the batch with a water bath (90-100ºC) at reflux. DMC has a boiling point of 90ºC, then it could be refluxed during the 1,25 hours needed, while CO escapes on the top of the column.
View user's profile View All Posts By User
monolithic
Hazard to Others
***




Posts: 119
Registered: 5-3-2018
Member Is Offline

Mood: No Mood

[*] posted on 8-4-2019 at 17:16


I may have found a very OTC source of dimethyl carbonate: Savogran Heavy Duty SuperStrip (non-DCM). The MSDS shows the following, by weight:

45-50% dimethyl carbonate (MP 3C, BP 90C)
30-35% 1,3-dioxolane (MP -95C, BP 75C)
15-20% methanol (MP -98C, BP 65C)

It seems to sell for about $16/quart at the big orange hardware store.
View user's profile View All Posts By User
wakatutu
Harmless
*




Posts: 24
Registered: 23-2-2017
Member Is Offline

Mood: Mostly Harmless

[*] posted on 8-4-2019 at 22:54


https://images.homedepot-static.com/catalog/pdfImages/da/da1...
savogran super strip (dcm-free)


https://images.homedepot-static.com/catalog/pdfImages/b2/b29...
savogran super strip dcm-free (CA)

The second one has methyl acetate, and its warning section says "Inhalation of Vapor May Cause Death" whereas the warning on the first one simply says inhalation causes dizziness and stuff like that.

I'm not 100% whether it's canada or california that has the methyl acetate version.

Great find, monolithic!
View user's profile View All Posts By User
clearly_not_atara
International Hazard
*****




Posts: 1563
Registered: 3-11-2013
Member Is Offline

Mood: No Mood

[*] posted on 17-4-2019 at 16:07


So I had a sudden realization.

Orthoesters are produced by reacting a nitrile with an alcohol in the presence of acid:

MeCN + 3 MeOH + H+ >> NH4+ + Et(OMe)3

Alkyl sulfonates are produced by reacting a sulfonic acid with an orthoester:

Et(OMe)3 + TsOH >> TsOMe + AcOMe + MeOH

Soooo... why can't these reactions happen in the same flask?

3 MeOH + 2 TsOH + MeCN >> TsOMe + NH4OTs + AcOMe + MeOH

The obvious objection is that ammonia will react with methyl tosylate. But with excess acid, there should be no ammonia present, only ammonium, which is not nucleophilic. Correspondingly, the rxn mixture cannot be neutralized; MeOTs must be distilled off directly. That should be fine, since MeOTs should be much more volatile than TsOH or ammonium tosylate but much less volatile than methanol or methyl acetate; i.e., no "azeotropes".




[Edited on 04-20-1969 by clearly_not_atara]
View user's profile View All Posts By User
AvBaeyer
National Hazard
****




Posts: 475
Registered: 25-2-2014
Location: CA
Member Is Offline

Mood: No Mood

[*] posted on 17-4-2019 at 16:57


Where is the reference to converting nitriles to orthoesters? Without that the above is just pointless bs.

AvB
View user's profile View All Posts By User
clearly_not_atara
International Hazard
*****




Posts: 1563
Registered: 3-11-2013
Member Is Offline

Mood: No Mood

[*] posted on 17-4-2019 at 22:09


It’s the Pinner reaction. But apparently HCl is required. However, the basic idea still has merit. If you perform the classic Pinner rxn to get the methyl acetimidate, you can use the anion metathesis here to convert it to the tosylate:

https://arca.unive.it/retrieve/handle/10278/38060/28512/c3gc...

Then adding methanol, heat, more TsOH should work. I guess this ultimately just replaces distilling the orthoester with solvent extraction of the alkyl imidate. But hey, it’s easier...

(Don’t use excess methanol in the imidate formation, it forms emulsions.)




[Edited on 04-20-1969 by clearly_not_atara]
View user's profile View All Posts By User
Loptr
International Hazard
*****




Posts: 1240
Registered: 20-5-2014
Location: USA
Member Is Offline

Mood: Grateful

[*] posted on 18-4-2019 at 18:04


This sort of reminds me of the synthesis of acetamidine starting from acetonitrile. The intermediate alkyl imitate reacts with excess ammonia form the imidine.

http://www.orgsyn.org/demo.aspx?prep=CV1P0005




"Question everything generally thought to be obvious." - Dieter Rams
View user's profile View All Posts By User
monolithic
Hazard to Others
***




Posts: 119
Registered: 5-3-2018
Member Is Offline

Mood: No Mood

[*] posted on 20-4-2019 at 21:00


Quote: Originally posted by wakatutu  
https://images.homedepot-static.com/catalog/pdfImages/da/da1...
savogran super strip (dcm-free)


https://images.homedepot-static.com/catalog/pdfImages/b2/b29...
savogran super strip dcm-free (CA)

The second one has methyl acetate, and its warning section says "Inhalation of Vapor May Cause Death" whereas the warning on the first one simply says inhalation causes dizziness and stuff like that.

I'm not 100% whether it's canada or california that has the methyl acetate version.

Great find, monolithic!


I didn't realize that, but yes it appears the California compliant models do not contain DMC and instead contain methyl acetate. You can see the model numbers here: https://savogran.com/removers.html :)
View user's profile View All Posts By User
 Pages:  1  2    4

  Go To Top