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

Printable Version  
Author: Subject: cyclic diester
ProChem
Harmless
*




Posts: 41
Registered: 9-6-2008
Location: Union Beach, NJ. USA
Member Is Offline

Mood: Cynical

[*] posted on 4-8-2009 at 07:00
cyclic diester


I have dimethyl ester ofadipic acid and ethylene glycol to make a cyclic diester (MSA is catalyst). any suggestions how one can avoid making a polymer?
View user's profile View All Posts By User
sonogashira
International Hazard
*****




Posts: 555
Registered: 10-9-2006
Member Is Offline

Mood: No Mood

[*] posted on 4-8-2009 at 08:08


High dilution with ethylene glycol will make cyclization more probable, but i do not know if the yield will be very high even still. Are 10-membered rings are very favorable? I would not imagine but i am not sure. But it is a known product i assume?

[Edited on 4-8-2009 by sonogashira]
View user's profile View All Posts By User
sparkgap
International Hazard
*****




Posts: 1234
Registered: 16-1-2005
Location: not where you think
Member Is Offline

Mood: chaotropic

[*] posted on 4-8-2009 at 21:34


Remember that forming rings larger than five or six atoms is not as kinetically or thermodynamically facile. I suggest looking into past work, e.g. http://www.google.com/patents?&vid=USPAT2092031&id=7... :)

HTH

sparky (~_~)




"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
View user's profile View All Posts By User
JohnWW
International Hazard
*****




Posts: 2849
Registered: 27-7-2004
Location: New Zealand
Member Is Offline

Mood: No Mood

[*] posted on 4-8-2009 at 22:58


Because of the mutual angle for tetrahedral sp3 bonding of 109º28', 5-membered (108º) and after that 6-membered (120º) rings are usually most favored energetically, if all four groups attached at the central sp3 atom are of similar size and polarity. Even then, 6-membered rings, and even more so 7-membered and larger rings, with all single bonds,, flex considerably out-of-plane in order for the constituent atoms to approach a bonding angle close to 109º28'.

[Edited on 5-8-09 by JohnWW]
View user's profile View All Posts By User
ProChem
Harmless
*




Posts: 41
Registered: 9-6-2008
Location: Union Beach, NJ. USA
Member Is Offline

Mood: Cynical

[*] posted on 14-10-2009 at 11:59


Shortly after I posted the question I found many patents I reacted sebacic acid and ethylene glycol (EG) with ptsa to make a polyester. The second step I heated the polyester with titanium isopropoxide under vacuum. Success! the next project I used 1,4-butane diol instead of EG. This time it didn't work however I collected THF as a product.
View user's profile View All Posts By User
ammonium isocyanate
Hazard to Others
***




Posts: 124
Registered: 13-7-2009
Location: USA - Midwest
Member Is Offline

Mood: sick :(

[*] posted on 14-10-2009 at 15:03


Could we see a write-up of your reaction?



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




Posts: 1567
Registered: 28-12-2010
Member Is Offline

Mood: No Mood

[*] posted on 8-1-2014 at 17:00


Quote: Originally posted by ProChem  
Shortly after I posted the question I found many patents I reacted sebacic acid and ethylene glycol (EG) with ptsa to make a polyester. The second step I heated the polyester with titanium isopropoxide under vacuum. Success! the next project I used 1,4-butane diol instead of EG. This time it didn't work however I collected THF as a product.


Tidbit on sebacic acid and glycerol -didn't know where to post this.
Surgical Glue to Mend Broken Hearts
http://www.technologyreview.com/news/523356/surgical-glue-to...
View user's profile View All Posts By User

  Go To Top