ProChem
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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?
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sonogashira
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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]
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sparkgap
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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..."
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JohnWW
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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]
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ProChem
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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.
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ammonium isocyanate
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Could we see a write-up of your reaction?
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Morgan
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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...
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