Patent ID: 6951857

Claim:
A process of marking an IL-5 receptor in biological material which comprises a) administering to said biological material a radiolabelled compound of formula (I) an N-oxide, a pharmaceutically acceptable addition salt, or a stereochemically isomeric form thereof, wherein: p represents 0, 1, or 2; q represents 0, 1, 2, or 3; R 1 represents hydrogen, C 1-6 alkyl, aryl, mono- or di(C 1-6 alkyl)aminoC 1-6 alkyl, or HetC 1-6 alkyl; R 2 represents 11 CN or 14 CN; each R 3 independently represents halo, haloC 1-6 alkyl, hydroxy, C 1-6 alkyl, C 1-6 alkyloxy, C 1-6 alkylcarbonyloxy, or aryl; each R 4 independently represents halo, haloC 1-6 alkyl, hydroxy, C 1-6 alkyl, C 1-6 alkyloxy, C 1-6 alkylcarbonyloxy, or aryl; aryl represents phenyl or phenyl substituted with one, two or three substituents selected from the group consisting of halo, hydroxy, mercapto, and C 1-6 alkyl; and Het represents imidazolyl, thiazolyl, piperazinyl, or benzothiazolyl substituted by phenyl or C 1-4 alkyl; and b) detecting the emissions from the radiolabelled compound.