Chemiluminescent probes for diagnostics and in vivo imaging

A compound of the formula I:

• wherein
• R1 is selected from the group consisting of a linear or branched (C1-C18)alkyl, and (C3-C7)cycloalkyl;
• R2 and R3 each independently is selected from the group consisting of a branched (C3-C18)alkyl and (C3-C7)cycloalkyl, or R2 and R3 together with the carbon atom to which they are attached form a fused, spiro or bridged cyclic or polycyclic ring;
• R5 and R6 each independently is selected from the group consisting of H, (C1-C18)alkyl, (C2-C18)alkenyl, (C2-C18)alkynyl, (C3-C7)cycloalkyl, and aryl, or R5 and R6 together with the oxygen atoms to which they are attached form a heterocyclic ring;
• R7, R8 and R9 each independently is H, or an electron acceptor group selected from the group consisting of halogen, —NO2, —CN, —COOR10, —C(═O)R10 and —SO2R10;
• R10 each independently is H or —(C1-C18)alkyl;
• and
• Q is a protecting group.

A compound of the formula IIa or IIb:

• wherein
• R1 is selected from the group consisting of a linear or branched (C1-C18)alkyl, and (C3-C7)cycloalkyl;
• R2 and R3 each independently is selected from the group consisting of a branched (C3-C18)alkyl and (C3-C7)cycloalkyl, or R2 and R3 together with the carbon atom to which they are attached form a fused, spiro or bridged cyclic or polycyclic ring;
• R4 is a protecting group:
• L is absent or is a linker of the formula L1, L2 or L3, optionally substituted at the aromatic ring with one or more substituents each independently selected from the group consisting of (C1-C18)alkyl and (C3-C7)cycloalkyl, wherein M is absent or is —O— or —NH—, and the asterisk represents the point of attachment to the group Y, provided that M is —O— or —NH— unless R4 is 4,4,5,5-tetramethyl-1,3,2-dioxaborolanyl or —B(OH)2;
• Y is absent or is —O—, provided that Y is —O— unless R4 is 4,4,5,5-tetramethyl-1,3,2-dioxaborolanyl or —B(OH)2, and L is absent;
• R7, R8 and R9 each independently is H, or an electron acceptor group selected from the group consisting of halogen, —NO2, —CN, —COOR10, —C(═O)R10 and —SO2R10;
• R10 each independently is H or —(C1-C18)alkyl;
• X is a linker of the formula —X1—X2—, wherein X1 is selected from the group consisting of (C1-C18)alkylene, (C2-C18)alkenylene, (C2-C18)alkynylene, (C3-C7)cycloalkylene, (C3-C7)cycloalkenylene, (C6-C14)arylene-diyl, (C1-C18)alkylene-(C6-C14)arylene-diyl, heteroarylenediyl, and (C1-C18)alkylene-heteroarylenediyl, said (C1-C18)alkylene, (C2-C18)alkenylene, (C2-C18)alkynylene, (C3-C7)cycloalkylene, (C3-C7)cycloalkenylene, (C6-C14)arylene-diyl, or heteroarylenediyl being optionally substituted by one or more groups each independently selected from the group consisting of halogen, —COR10, —COOR10, —OCOOR10, —OCON(R10)2, —CN, —NO2, —SR10, —OR10, —N(R10)2, —CON(R10)2, —SO2R10, —SO3H, —S(═O)R10, (C6-C10)aryl, (C1-C4)alkylene-(C6-C10)aryl, hetero aryl, and (C1-C4)alkylene-hetero aryl, and said (C1-C18)alkylene, (C2-C18)alkenylene, or (C2-C18)alkynylene being further optionally interrupted by one or more identical or different heteroatoms selected from the group consisting of S, O and N, and/or at least one group each independently selected from the group consisting of —NH—CO—, —CO—NH—, —N(C1-C8alkyl)-, —N(C6-C10aryl)-, (C6-C10arylene-diyl, and heteroarylenediyl;
• and X2 is absent or is —C(O)—;
• and
• R14 is a reactive group such as —O—(C1-C18)alkyl, —N3, —C≡CH, N-succinimidyloxy, 3-sulfo-N— succinimidyloxy, pentafluorophenyloxy, 4-nitrophenyloxy, N-imidazolyl, and N-1H-benzo[d][1,2,3]triazoloxy.

A conjugate of the formula IIIa or IIIb:

• wherein
• R1 is selected from the group consisting of a linear or branched (C1-C18)alkyl, and (C3-C7)cycloalkyl;
• R2 and R3 each independently is selected from the group consisting of a branched (C3-C18)alkyl and (C3-C7)cycloalkyl, or R2 and R3 together with the carbon atom to which they are attached form a fused, spiro or bridged cyclic or polycyclic ring;
• R4 is a caging group;
• L is absent or is a linker of the formula L1, L2 or L3, optionally substituted at the aromatic ring with one or more substituents each independently selected from the group consisting of (C1-C18)alkyl and (C3-C7)cycloalkyl, wherein M is absent or is —O— or —NH—, and the asterisk represents the point of attachment to the group Y, provided that M is —O— or —NH— unless R4 is 4,4,5,5-tetramethyl-1,3,2-dioxaborolanyl or —B(OH)2;
• Y is absent or is —O—, provided that Y is —O— unless R4 is 4,4,5,5-tetramethyl-1,3,2-dioxaborolanyl or —B(OH)2, and L is absent;
• R7, R8 and R9 each independently is H, or an electron acceptor group selected from the group consisting of halogen, —NO2, —CN, —COOR10, —C(═O)R10 and —SO2R10;
• R10 each independently is H or —(C1-C18)alkyl;
• X is a linker of the formula —X1—X2—, wherein X1 is selected from the group consisting of (C1-C18)alkylene, (C2-C18)alkenylene, (C2-C18)alkynylene, (C3-C7)cycloalkylene, (C3-C7)cycloalkenylene, (C6-C14)arylene-diyl, (C1-C18)alkylene-(C6-C14)arylene-diyl, heteroarylenediyl, and (C1-C18)alkylene-heteroarylenediyl, said (C1-C18)alkylene, (C2-C18)alkenylene, (C2-C18)alkynylene, (C3-C7)cycloalkylene, (C3-C7)cycloalkenylene, (C6-C14)arylene-diyl, or heteroarylenediyl being optionally substituted by one or more groups each independently selected from the group consisting of halogen, —COR10, —COOR10, —OCOR10, —OCON(R10)2, —CN, —NO2, —SR10, —OR10, —N(R10)2, —CON(R10)2, —SO2R10, —SO3H, —S(═O)R10, (C6-C10)aryl, (C1-C4)alkylene-(C6-C10)aryl, hetero aryl, and (C1-C4)alkylene-hetero aryl, and said (C1-C18)alkylene, (C2-C18)alkenylene, or (C2-C18)alkynylene being further optionally interrupted by one or more identical or different heteroatoms selected from the group consisting of S, O and N, and/or at least one group each independently selected from the group consisting of —NH—CO—, —CO—NH—, —N(C1-C8alkyl)-, —N(C6-C10aryl)-, (C6-C10arylene-diyl, and heteroarylenediyl;
• and X2 is absent or is —C(O)—;
• and
• Z is a moiety of a fluorophore selected from the group consisting of a fluorescein-based compound, rhodamine-based compound, coumarin-based compound, cyanine dye selected from the group consisting of Cy5, Cy5.5, Cy5.18, Cy7, Cy7.18, and QCy, or boron-dipyrromethene.