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

Printable Version  
 Pages:  1    3
Author: Subject: Substitute for dioxane
Baphomet
Hazard to Others
***




Posts: 211
Registered: 19-11-2006
Member Is Offline

Mood: No Mood

[*] posted on 8-1-2011 at 14:46
Substitute for dioxane


I'm about to run out of 1,4-dioxane which is a wonderfully toxic and versatile polar aprotic solvent that is now hard to find outside of chemical suppliers.

Are there any good substitutes? Note that I'm not just after dissolution ability but a low level of chemical reactivity. I'm here scratching my head but all the other solvents that fit the bill are even less 'OTC' than dioxane.




\"Who ARE you? You\'re like the drummer from REO Speedwagon - nobody knows who you are\" from \'Employee of the Month\'
View user's profile View All Posts By User
Ozone
International Hazard
*****




Posts: 1267
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline

Mood: Integrated

[*] posted on 8-1-2011 at 16:56


How about glyme (1,2-dimethoxyethane)?



-Anyone who never made a mistake never tried anything new.
--Albert Einstein
View user's profile View All Posts By User
BromicAcid
International Hazard
*****




Posts: 3001
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline

Mood: Anxious

[*] posted on 8-1-2011 at 20:17


How about making it? Frogfot had a good procedure for it when his site was up, still available by the wayback archive:

http://web.archive.org/web/20071011001804/www.frogfot.com/sy...

Dioxane is pretty toxic but it's all relative compared to what you're using it for obviously. When my I told my doctor I was a chemist he was worried about exposure to solvents, little did he know what nasties I use the solvents with.




Shamelessly plugging my attempts at writing fiction: http://www.robvincent.org
View user's profile Visit user's homepage View All Posts By User
garage chemist
chemical wizard
*****




Posts: 1803
Registered: 16-8-2004
Location: Germany
Member Is Offline

Mood: No Mood

[*] posted on 9-1-2011 at 08:13


There is a german synthesis of dioxane on Lambdasyn which is similar to frogfots method, but uses a mix of 225ml ethylene glycol and 6ml sulfuric acid. Quite surprising how little acid is needed to make this ether.

Whether you can find a substitute depends on the application.
Glyme and Diglyme sound good, but they're hard to get (for me at least) and can't be made at home (well, unless you're prepared to methylate glycol or diglycol with dimethyl sulfate).
Normally I would recommend dioxane as a substitute for glymes.




www.versuchschemie.de
Das aktivste deutsche Chemieforum!
View user's profile View All Posts By User
Baphomet
Hazard to Others
***




Posts: 211
Registered: 19-11-2006
Member Is Offline

Mood: No Mood

[*] posted on 10-1-2011 at 01:28


Thanks guys! I like that synth.. will try it out and report the results later.




\"Who ARE you? You\'re like the drummer from REO Speedwagon - nobody knows who you are\" from \'Employee of the Month\'
View user's profile View All Posts By User
maxidastier
Hazard to Others
***




Posts: 118
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 14-7-2011 at 09:42


Does it make sense to carry out the synthesis under lower pressure to minimize the formation of those nasty by-products?
View user's profile View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10334
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 14-7-2011 at 13:13


Quote: Originally posted by garage chemist  
There is a german synthesis of dioxane on Lambdasyn [...]


Where precisely? I looked for it sometime ago and couldn't find it!
View user's profile Visit user's homepage View All Posts By User
garage chemist
chemical wizard
*****




Posts: 1803
Registered: 16-8-2004
Location: Germany
Member Is Offline

Mood: No Mood

[*] posted on 14-7-2011 at 15:07


It's here:
http://www.lambdasyn.org/synfiles/dioxan.htm

It's a lot of work even if it seems easy. Several treatments with KOH are necessary to seperate most of the water. If there's a better way to remove large amounts of water from dioxane, I'd like to know it. CaCl2 forms a complex with dioxane.




www.versuchschemie.de
Das aktivste deutsche Chemieforum!
View user's profile View All Posts By User
maxidastier
Hazard to Others
***




Posts: 118
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 15-7-2011 at 01:39



Quote:

If there's a better way to remove large amounts of water from dioxane, I'd like to know it.
.

Molecular Sieve 4A... for 1 liter around 100g

But still:
Quote:

Does it make sense to carry out the synthesis under lower pressure to minimize the formation of those nasty by-products?


[Edited on 15-7-2011 by maxidastier]
View user's profile View All Posts By User
plastics
Hazard to Others
***




Posts: 134
Registered: 6-11-2009
Member Is Offline

Mood: No Mood

[*] posted on 15-7-2011 at 01:41


I have done the frogfot method with 1000ml MEG and got approx 400ml of very dry dioxane

Don't overdo the sulphuric acid as mentioned otherwise you end up with black goo very quickly

As garage chemist says it is quite an effort to get all the water out and you get a fair amount of sticky orange polymerised ethanal as well

As the frogfot method states use a Vigreux column for the initial separation and distil the final nearly dry product off Na metal or KOH. Judging by the BP and smell (!?) of the final product it seems quite pure

[Edited on 15-7-2011 by plastics]
View user's profile View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 15-7-2011 at 07:03


I suspect p-TsOH can be used to advantage in place of sulfuric acid. You should get less charring and higher yields, as the acid is not dehydrating or oxidising. MsOH may also find use in this synthesis.
View user's profile View All Posts By User
maxidastier
Hazard to Others
***




Posts: 118
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 15-7-2011 at 09:38


I know that it works better with p-TsOH, but I simply cannot get that stuff...so
Does it make sense to carry out the synthesis under lower pressure to minimize the formation of those nasty by-products?
View user's profile View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10334
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 15-7-2011 at 09:47


Quote: Originally posted by garage chemist  
It's here:
http://www.lambdasyn.org/synfiles/dioxan.htm

It's a lot of work even if it seems easy. Several treatments with KOH are necessary to seperate most of the water. If there's a better way to remove large amounts of water from dioxane, I'd like to know it. CaCl2 forms a complex with dioxane.


The frogfot procedure uses K2CO3, IIRW...
View user's profile Visit user's homepage View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 15-7-2011 at 11:17


Quote: Originally posted by maxidastier  
I know that it works better with p-TsOH, but I simply cannot get that stuff...so
Does it make sense to carry out the synthesis under lower pressure to minimize the formation of those nasty by-products?


Can you get toluene?

http://www.sciencemadness.org/talk/viewthread.php?tid=11878

Even crude TsOH, containing some o- and m- isomers, generally is OK for use as a catalyst.

Higher yields of the para isomer are obtained by passing toluene vapour through H2SO4 at 150-160 C, with excess toluene removing the water formed as the azeotrope, taking care to stop at about 95% conversion of the H2SO4 (measure the amount of water distilled off) to minimise poly-sulfonation.


View user's profile View All Posts By User
maxidastier
Hazard to Others
***




Posts: 118
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 19-7-2011 at 07:52


No, I can not get toluene. It's restricted in Germany for "common people". Fuck it!
View user's profile View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10334
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 19-7-2011 at 08:37


If it 'works better' with TsOH, what precisely does that mean? In what respect is it preferable to conc. H2SO4 that justifies making the TsOH in the first place? In what way would the synth. of dioxane be modified, using TsOH instead of conc. H2SO4?

[Edited on 19-7-2011 by blogfast25]
View user's profile Visit user's homepage View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 19-7-2011 at 12:24


If you read my post you'll notice I mention the criteria on which TsOH makes a better catalyst. Its a non-oxidising, non-dehydrating acid with a pKa similar to that of sulfuric acid. This means you'd expect a cleaner reaction and as such a higher yield of the deisred product.
View user's profile View All Posts By User
tmb
Harmless
*




Posts: 36
Registered: 25-2-2011
Member Is Offline

Mood: No Mood

[*] posted on 19-7-2011 at 13:09


What is the yield with TsOH?
Is a dehydrating acid not preferred? Since the aim is to remove water?!
View user's profile View All Posts By User
maxidastier
Hazard to Others
***




Posts: 118
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 23-7-2011 at 06:26



Quote:

1,4-dioxane was synthesis by dehydration of ethanediol using p-toluene sulphonic acid as the catalyst.Influence of catalyst dosage,reaction temperature and reaction time on the yield was investigated.The optimum reaction condition was as follows: catalyst dosage=4.3% of the amount of ethanediol,reaction time 50 min.1,4-dioxane yield of 84.82% was obtained under the optimum condition.


http://61.185.219.126:88/qikan/epaper/zhaiyao.asp?bsid=14647

Can someone get that paper or tell me how to do it?
View user's profile View All Posts By User
maxidastier
Hazard to Others
***




Posts: 118
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 29-7-2011 at 08:29


ok, then. How many grams of TsOH would you use for dehydrating 200ml ethanediol?
View user's profile View All Posts By User
Nicodem
Super Moderator
*******




Posts: 4229
Registered: 28-12-2004
Member Is Offline

Mood: No Mood

[*] posted on 29-7-2011 at 11:55


Quote: Originally posted by maxidastier  
ok, then. How many grams of TsOH would you use for dehydrating 200ml ethanediol?

Hm, have you bothered reading that abstract you quote? It says it all right there!
Quote: Originally posted by maxidastier  
http://61.185.219.126:88/qikan/epaper/zhaiyao.asp?bsid=14647

Can someone get that paper or tell me how to do it?

You click on the link for the full text and it downloads. You need a PDF viewer installed to view the article.

PS: Are you sure you are able to conduct chemical experiments safely? I would suggest you to first work on your general skills.
View user's profile View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 29-7-2011 at 13:00


I've just checked myself what the issue is and it won't allow you to download. Anyone have access?
View user's profile View All Posts By User
Nicodem
Super Moderator
*******




Posts: 4229
Registered: 28-12-2004
Member Is Offline

Mood: No Mood

[*] posted on 29-7-2011 at 13:17


Quote: Originally posted by DJF90  
I've just checked myself what the issue is and it won't allow you to download. Anyone have access?

Could be IP country dependent. Looks like the Chinese like my IP:

Attachment: gych02006.pdf (349kB)
This file has been downloaded 421 times

View user's profile View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 29-7-2011 at 15:48


Thanks - no good to me as its only the abstract in English. Should be sufficient to give it a go if necessary though.
View user's profile View All Posts By User
maxidastier
Hazard to Others
***




Posts: 118
Registered: 3-4-2010
Member Is Offline

Mood: No Mood

[*] posted on 3-8-2011 at 08:18


Thank you anyway Nicodem. I'm not that stupid as it seems. I just don't like making experiments with only an abstract ;)
View user's profile View All Posts By User
 Pages:  1    3

  Go To Top