Patent ID: 7041821

Claim:
A compound having the structure: wherein: each of X 1 and X 2 is independently F, Cl, Br, or I; X 3 is NHCH 2 R, or NHSO 2 R, wherein R is a five or six-membered heterocyclic ring; X 4 is NHCH 2 R, or NHSO 2 R, wherein R is as defined above, Y 1 and Y 2 taken together are —O—, —S—, —Se—, —CMe 2 -, —NH—, —NMe-, or —NPh-; A is wherein: Z 1 is H, CO 2 H, or SO 3 H; each of Z 2 and Z 5 is independently H, F, or Cl; each of Z 3 and Z 4 is independently H, F, Cl, CO 2 H, NO 2 , NH 2 , NCS, NHCOCH 2 I, SCH 2 OOOH, SCH 2 CH 2 NH 2 , (N-succinimidyl)oxycarbonyl, (N-succinimidyl)oxycarbonylmethylthio, N-maleimidyl, or 3,5-dichloro-2,4,6-triazinylamino, or tautomers and physiologically acceptable salts thereof.