Patent ID: 8039579

Claim:
A Diels-Alder adduct-containing polymer of the following structure: wherein: POLY is a water soluble and non-peptidic polymer (i) terminating in either a hydroxyl group or end capping group selected from the group consisting of methoxy, ethoxy, butyloxy and benzyloxy, (ii) having a weight average molecular weight of greater than 4,000 Daltons and less than about 300,000 Daltons, and (iii) is selected from the group consisting of poly(alkylene glycol), poly(olefinic alcohol), poly(vinylpyrrolidone), poly(hydroxyalkylmethacrylamide), poly(hydroxyalkylmethacrylate), poly(α-hydroxyacetic acid), poly(acrylic acid), poly(vinyl alcohol), polyphosphazene, polyoxazoline, poly(N-acryloylmorpholine), and copolymers or terpolymers thereof; L is a linkage comprising -L 1 -L 2 -, wherein L 1 comprises a linkage selected from the group consisting of a heteroatom linkage, an amide linkage, an amine linkage, a urethane linkage and a urea linkage, and L 2 is a saturated acyclic or alicyclic hydrocarbon chain adjacent to the nitrogen atom of the Diels-Alder adduct, the hydrocarbon chain comprising a bivalent saturated cycloalkyl group, an alkylene group, or a combination thereof, and having a total number of carbons ranging from 1 to about 30; X is selected from the group consisting of alkylene, substituted alkylene, alkenylene, substituted alkenylene, —C(O)—, heteroatom, substituted heteroatom and two hydrogens, wherein one of the two hydrogens attached to the carbon bearing R 1 and the other to the carbon bearing R 4 ; and each of R 1 , R 2 , R 3 and R 4 is independently selected from the group consisting of H, halo, hydroxyl, carboxyl, carboxylalkyl, thiol, alkylthio, acyl, acyloxy, nitro, cyano, azido, trihalomethyl, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkoxy, aryl, substituted aryl, heterocycle, substituted heterocycle, heteroaryl, and substituted heteroaryl.