Dye labeled imidazoquinoline compounds

A compound of the formula (I):

• 10
• wherein:
• R1 is a spacer group;
• R2 is hydrogen, alkyl, hydroxyalkyl, haloalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, amidoalkyl, alkylamidoalkyl, dialkylamidoalkyl, alkanoylalkyl, azidoalkyl, carbamoylalkyl, alkyl optionally interrupted by a heteroatom;
• alkenyl, alkenyloxyalkyl;
• cycloalkylalkyl, heterocycloalkyl;
• aryl, aralkyl, aralkenyl, heteroarylalkyl, in which aryl is optionally substituted by alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, halo, amino, alkylamino or dialkylamino;
• aroylalkyl, or heteroaroylalkyl;
• R3 and R4 are each independently hydrogen, alkyl, alkoxy of 1 to 4 carbon atoms, halo, amino, alkylamino, dialkylamino, or when taken together, R3 and R4 form a fused aryl or heteroaryl group that is optionally substituted by one or more substituents selected from alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, halo, amino, alkylamino, dialkylamino, hydroxy and alkoxymethyl;
• or
• R3 and R4 for a fused 5- to 7-membered saturated ring, optionally containing one or more heteroatoms and optionally substituted by one or more substituents selected from alkyl of 1 to 4 carbon atoms, halo or haloalkyl of 1 to 4 carbon atoms;
• and
• DYE is a dye moiety, with the proviso that the dye moiety is not dansyl;
• or a pharmaceutically acceptable acid addition salt thereof.