Patent ID: 6864393

Claim:
A compound of Formula I or a pharmaceutically acceptable salt thereof, wherein, R 1 is selected from the group consisting of hydroxy(C 1-4 )alkyl, halo(C 1-4 )alkyl, nitro, azido, halo or —NR 6 R 7 wherein, R 6 and R 7 are each independently selected from the group consisting of hydrogen, C 1-4 alkyl, halo(C 1-4 )alkyl, halo(C 1-4 )alkanoyl and halobenzoyl, R 2 is —NR 8 R 9 wherein, R 8 and R 9 are each independently selected from the group consisting of hydrogen, C 1-4 alkyl, halo(C 1-4 )alkyl, halo(C 1-4 )alkanoyl and halobenzoyl, R 3 is independently selected from the group consisting of hydrogen, halo, cyano, C 1-4 alkyl, halo(C 1-4 )alkanoyl and (C 1-4 )alkoxy, R 4 and R 5 are each independently selected from the group consisting of hydrogen, halo, cyano, C 1-4 alkyl, halo(C 1-4 )alkanoyl and (C 1-4 )alkoxy, and X is hydrogen or halo, provided that: one of R 1 , R 2 , R 3 , R 4 , R 5 or X contains 18 F, and if R 1 is —NR 6 R 7 wherein R 6 and R 7 are both hydrogen, and R 2 is —NR 8 R 9 wherein R 8 and R 9 are both methyl, then R 3 is hydrogen, halo, cyano, C 1-4 alkyl, or (C 1-4 )alkoxy, and if R 1 is fluoromethyl, then R 3 and X are other than 4-iodine.