Patent ID: 8088741

Claim:
A compound having a structure of formula (III) or a pharmaceutically acceptable salt thereof wherein each Ar is independently an aromatic or heteroaromatic group optionally substituted with 1-4 substituents; L is selected from C═O, C═S, and SO 2 ; X is selected from O, S, NH, and N—C 1-6 alkyl; Y is absent or is selected from C═O and SO 2 ; Z is absent or is C 1-6 alkyl; R 1 , R 2 , and R 3 are each independently selected from C 1-6 alkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxyalkyl, aryl, and C 1-6 aralkyl, any of which is optionally substituted with one or more of amide, amine, carboxylic acid (or a salt thereof), ester, thiol, or thioether substituents; R 4 is N(R 5 )L—Z—R 6 ; R 5 is selected from hydrogen, OH, C 1-6 aralkyl-Y-, and C 1-6 alkyl-Y-; R 6 is selected from OR 7 , C 2-6 alkenyl, Ar—Y—, carbocyclyl, and heterocyclyl; and R 7 and R 8 are independently selected from hydrogen and C 1-6 alkyl.