	US 7,541,422 B2
	Enzyme-catalyzed process for the preparation of macrocyclic polyester oligomers
Robert DiCosimo, Chadds Ford, Pa. (US); Scott Christopher Jackson, Wilmington, Del. (US); and Anna Panova, Hockessin, Del. (US)
Assigned to E. I. du Pont de Nemours and Company, Wilmington, Del. (US)
Filed on Jun. 01, 2006, as Appl. No. 11/444,631.
Claims priority of provisional application 60/688220, filed on Jun. 07, 2005.
Prior Publication US 2007/0021584 A1, Jan. 25, 2007
Int. Cl. C08G 63/02 (2006.01); C08G 64/00 (2006.01)

U.S. Cl. 528—272 [424/451; 424/456; 435/18; 435/134; 435/136; 524/589; 524/732; 524/768; 528/271; 528/274]

24 Claims

1. A process for the production of cyclic ester oligomers, comprising the step of reacting in a solvent components comprising:

(a) a first component selected from one or more of:

(i) at least one dicarboxylic acid and/or dicarboxylic acid derivative and at least one diol,

(ii) at least one hydroxycarboxylic acid and/or hydroxycarboxylic acid ester, and

(iii) at least one linear ester oligomer; and

(b) a second component comprising at least one enzyme capable of catalyzing transesterification of esters, esterification of carboxylic acids, and/or hydrolysis of esters;

wherein the solvent comprises about 30 to about 70 weight percent of at least one tertiary alcohol and about 30 to about 70 weight percent of at least one non-alcoholic solvent, wherein the weight percentages are based on the total weight of the solvent.