Patent ID: 8153784

Claim:
A monomeric substrate of formula (I): wherein X is selected from the group consisting of 1,4,7,10-tetraazacyclodo-decane-N,N′,N″,N′″-tetraacetic acid, 1,4,7,10-tetraaza-cyclododecane-N,N′,N″-triacetic acid, 1,4,7-tris(carboxymethyl)-10-(2′-hydroxypropyl)-1,4,7,10-tetraazacyclododecane, and 1,4,8,11-tetraazacyclotetra-decane-N,N′,N″,N′″-tetraacetic acid; Y comprises a linker moiety; each of R 1 , R 2 , R 3 , and R 4 is selected from the group consisting of hydrogen, hydroxy, C 1 -C 6 alkoxy, amino, C 1 -C 6 alkylamino, C 1 -C 6 dialkylamino, and C 1 -C 6 alkylcarboxamido; provided that at least one of R 1 , R 2 , R 3 , and R 4 is hydroxyl; A is: wherein B is CR a R b or NR c ; R d is hydrogen or R d together with one of R a , R b or R c is a bond; G is NR e , O, or S; each of R a and R b is, independently, hydrogen, C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, C 1 -C 4 haloalkyl, C 7 -C 12 aralkyl, 6-12 membered heteroaralkyl, 3-8 membered heterocyclyl, C 3 -C 8 cycloalkenyl, 3-8 membered heterocycloalkenyl, C 6 -C 12 aryl, 5-12 membered heteroaryl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, 7-12 membered aryloxy, 7-12 membered thioaryloxy, C 1 -C 4 haloalkoxy, halo, hydroxy, carboxy, carboxylate, aminocarbonyl, C 1 -C 4 alkylaminocarbonyl, dialkylaminocarbonyl, C 1 -C 6 alkoxycarbonyl, cyano, nitro, amino, C 1 -C 4 alkyl amino, C 1 -C 4 dialkyl amino, mercapto, C 1 -C 6 thioalkoxy, SO 3 H, sulfate, or phosphate; or one of R a and R b is hydrogen, C 1 -C 6 alkyl, C 3 -C 8 cycloalkyl, haloalkyl, C 7 -C 12 aralkyl, 6-12 membered heteroaralkyl, 3-8 membered heterocyclyl, C 3 -C 8 cycloalkenyl, 3-8 membered heterocycloalkenyl, C 6 -C 12 aryl, 5-12 membered heteroaryl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, 7-12 membered aryloxy, 7-12 membered thioaryloxy, C 1 -C 4 haloalkoxy, halo, hydroxy, carboxy, carboxylate, aminocarbonyl, C 1 -C 4 alkylaminocarbonyl, C 1 -C 4 dialkylaminocarbonyl, C 1 -C 6 alkoxycarbonyl, cyano, nitro, amino, C 1 -C 4 alkyl amino, C 1 -C 4 dialkyl amino, mercapto, C 1 -C 6 thioalkoxy, SO 3 H, sulfate, or phosphate, and the other together with R d is a bond; R c is hydrogen or C 1 -C 6 alkyl; or R c together with R d is a bond; and R e is hydrogen or C 1 -C 6 alkyl.