Acetylenedicarboxyl linkers and their uses in specific conjugation of a cell-binding molecule

A compound of Formula (III):

• wherein:
• Cb represents a cell-binding agent selected from the group consisting of an antibody, a protein, a vitamin, and a peptide, each of which optionally coated on a polymeric micelle, a liposome, a lipoprotein-based drug carrier, a nano-particle drug carrier, or a dendrimer, and a combination thereof;
• Z1 and Z2 are the same or different and represent a functional group that enables the compound to react with a cytotoxic drug, to form a disulfide, thioether, thioester, peptide, hydrazone, ether, ester, carbamate, carbonate, secondary, tertiary, or quarter amine, imine, cycloheteroalkyl, heteroaromatic, alkyloxime or amide bond;
• n is 1 to 20;
• R1 and R2 are the same or different, and are absent, a linear alkyl having from 1 to 6 carbon atoms;
• branched or cyclic alkyl having from 3 to 6 carbon atoms;
• linear, branched or cyclic alkenyl or alkynyl having from 2 to 6 carbon atoms;
• ester, ether, or amide having from 2 to 6 carbon atoms;
• or polyethyleneoxy unit of formula (OCH2CH2)p, wherein p is an integer from 1 to about 1000, or a combination thereof;
• and
• X1 and X2 are independently NH, N(R3), O, S or CH2;
• R3 is H, a linear alkyl having from 1 to 6 carbon atoms;
• branched or cyclic alkyl having from 3 to 6 carbon atoms;
• linear, branched or cyclic alkenyl or alkynyl having from 2 to 6 carbon atoms;
• or esters, ether, amide having from 2 to 6 carbon atoms;
• or polyethyleneoxy unit of formula (OCH2CH2)p, wherein p is an integer from 0 to about 1000, or a combination thereof,
• wherein Z1 and Z2 each are represented by one of following structures:
• N-hydroxysuccinimide ester,
• maleimide;
• disulfide;
• haloacetyl;
• acyl halide (acid halide),
• ethenesulfonyl;
• acryl (acryloyl);
• 2-(tosyloxy)acetyl;
• 2-(mesyloxy)acetyl;
• 2-(nitrophenoxy)acetyl;
• 2-(dinitrophenoxy)acetyl;
• 2-(fluorophenoxy)-acetyl;
• 2-(difluorophenoxy)-acetyl;
• 2-(((trifluoromethyl)-sulfonyl)oxy)acetyl;
• ketone, or aldehyde,
• 2-(pentafluorophenoxy)-acetyl;
• methylsulfone phenyloxadiazole (ODA);
• acid anhydride,
• alkyloxyamino;
• azido,
• alkynyl, or
• hydrazide,
• wherein X1′ is F, Cl, Br, I or Lv;
• X2′ is O, NH, N(R1), or CH2;
• R5 and R4 are H, R1, or an aromatic, heteroaromatic, or aromatic group wherein one or several H atoms are replaced independently by —R1, -halogen, —OR1, —SR1, —NR1R2, —NO2, —S(O)R1, —S(O)2R1, or —COOR1;
• Lv is a leaving group selected from nitrophenol;
• N-hydroxysuccinimide;
• phenol;
• dinitrophenol;
• pentafluorophenol;
• tetrafluorophenol;
• difluorophenol;
• monofluorophenol;
• pentachlorophenol;
• triflate;
• imidazole;
• dichlorophenol;
• tetrachlorophenol;
• 1-hydroxybenzotriazole;
• tosylate;
• mesylate;
• 2-ethyl-5-phenylisoxazolium-3′-sulfonate, an anhydride;
• or an intermediate molecule generated from any of the above with a condensation reagent for peptide coupling reactions or for Mitsunobu reactions.