Glycolic anhydride diacetate

Cyclohexadiene has been prepared by dehydration of cyclohexen-3-ol,3 by pyrolysis at 540° of the diacetate of cyclohexane-1,2-diol,4 by dehydrobromination with quinoline of 3-hromocyclohexene,6 by treating the ethyl ether of cyclohexen-3-ol with potassium bisulfatc,6 7 by heating cyclohexene oxide with phthalic anhydride,8 by treating cyclohexane-1,2-diol with concentrated sulfuric acid,9 by treatment of 1,2-dibromocyclo-hexane with tributylamine,10 with sodium hydroxide in ethylene glycol,10 and with quinoline,6 and by treatment of 3,6-dibromo-cyclohexene with sodium.6... 

The major concern about applying this reaction to a polyether molecule is therefore how extensive this reaction will repeat itself randomly to all of the available ether bonds. Other questions include the necessity of excess anhydride, the rather low reported yield, and the catalyst dosage. These are crucial questions for an acceptable industrial process and failure can hamper the project seriously. On the other hand, if successful, then post-consumer foams, which represent an enormous problem for most recycling efforts, can be converted to the more valuable glycol diacetate. 

In addition to pyromellitic dianhydride (PMDA), three other dianhydrides were used to extend the polyester segments. These anhydrides were prepared by heating trimellitic arihydride (IV) with glycol diacetates (V) (6) ... 

A reaction vessel was charged with maleic anhydride (20 g), 1,4-dihydro-1,4-metha-no-naphthalene-5,8-diol diacetate (26 g), and propylene glycol methylether acetate (26 g), and then treated with 2,2 -azobissobutyronitrile (0.5 g). The mixture was reacted at 65°C for 7 hours, concentrated, precipitated in water, washed with diethyl ether, and the product was isolated in 40% yield, M of roughly 7000 daltons. 

CARBONIC ACID, LITHIUM SALT (554-13-2) LijCOj Aqueous solution is an organic base. Violent reaction with acids. Inconpatible with fluorine, germanium, lead diacetate, magnesium, mercurous chloride, silicon, silver nitrate, titanium. Aqueous solution incompatible with organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, cellulose nitrate, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, isocyanates, ketones, glycols, nitrates, phenols, vinyl acetate. Exothermic decomposition with maleic anhydride. Corrodes aluminum, copper, zinc in the presence of moisture. On small fires, use any extinguishing agent. 

---