4h-imidazo[1,5-b]pyrazole derivatives for diagnosis

A compound of formula (III-F) or (III-F′)

• or a stereoisomer, racemic mixture, pharmaceutically acceptable salt, hydrate, or solvate thereof, wherein
• is a 6-membered heteroaryl;
• which is optionally substituted with at least one substituent independently selected from halo, or C1-C4alkyl
• R1F is a 4- to 6-membered heterocyclyl or C1-C4alkoxy;
• R2 is a 5-membered or 6-membered heteroaryl optionally substituted with 1 or 2 substituents independently selected from haloC1-C4alkyl, haloC1-C4alkoxy, C1-C4alkoxy, and C1-C4alkyl;
• LG is a leaving group, which is preferably selected from bromo, chloro, iodo, C1-C4alkylsulfonate and C6-C10arylsulfonate, wherein the C6-C10arylsulfonate can be optionally substituted with —CH3 or —NO2;
• and
• n is at least 1.

A compound of formula (III-H)

• or a stereoisomer, racemic mixture, pharmaceutically acceptable salt, hydrate, or solvate thereof, wherein
• is a 6-membered heteroaryl which is optionally substituted with at least one substituent independently selected from halo, or C1-C4alkyl;
• R1 is halo or a 4- to 6-membered heterocyclyl which is optionally substituted with at least one halo, or haloC1-C4alkoxy;
• R2 is a 5-membered or 6-membered heteroaryl, optionally substituted with 1 or 2 substituents independently selected from haloC1-C4alkyl, haloC1-C4alkoxy, C1-C4alkoxy, and C1-C4alkyl;
• m is 0, 1, or 2;
• p is 0, 1, or 2;
• and
• X is bromo, chloro or iodo;
• with the proviso that the compound of formula (III-H) comprises at least one X.