Compounds for fluorescent labeling

A compound of Formula I:

• wherein
• X and Y are independently selected from halogen, OH, C1-20alkyl, C2-20alkenyl, C2-20alkynyl, C1-20alkoxy, C2-20alkenyloxy, C2-20alkynyloxy, C3-20cycloalkyl, C3-20cycloalkoxy, C6-20aryl and C6-20aryloxy;
• R1, R2, R3, R4, R5 and R6 are independently selected from H, halogen, OPg, C1-20alkyl, C2-20alkenyl, C2-20alkynyl, C3-20cycloalkyl, heteroaryl, heterocyclyl and C6-20aryl, or any two adjacent R1, R2, R3, R4, R5 and R6 groups are joined together to form a 3-20 membered ring system;
• Pg is a suitable protecting group;
• R7 is selected from C1-20alkyl and (CH2)2CN;
• R8 and R9 are independently selected from C1-20alkyl and C3-20cycloalkyl;
• Z is selected from C1-20alkylene and C6-24arylene;
• and
• each alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl and heterocyclyl, alone or part of another group, and the ring system, is unsubstituted or substituted with one or more substituents independently selected from halogen, OPg, C1-6alkyl, C1-6alkoxy and C6-10aryl,
• or a salt or solvate thereof.