Patent ID: 7893086

Claim:
A compound represented by Structural Formula (II): or a salt thereof, wherein: two of X 1 to X 4 are selected from —CR*— and —N—; the other two of X 1 to X 4 are —CR*—; R* is independently selected at each occurrence from —H, lower alkyl or halogen; R 1 is a solubilizing group; and R 2 is selected from phenyl optionally substituted with one or more substituents independently selected from —CN, —F, —Cl and —CF 3 , and when each of X 1 to X 4 is —CR*—, R 2 is additionally selected from a 5- to 6-membered heterocycle containing an N heteroatom and, optionally, a second heteroatom selected from N, O or S, wherein said heterocycle is optionally substituted with methyl.