Compounds

摘要

Compounds of the formulae Ia and Ib: wherein: A is CH2, or a single bond; R2 is selected from: R, OH, OR, CO2H, CO2R, COH, COR, SO2R, CN; R6, R7 and R9 are independently selected from H, R, OH, OR, halo, amino, NHR, nitro, Me3Sn; and R8 is selected from H, R, OH, OR, halo, amino, NHR, nitro, Me3Sn, where R is as defined above, or the compound is a dimer with each monomer being the same or different and being of formula Ia or Ib, where the R8 groups of the monomers form together a bridge having the formula -X-R'-X- linking the monomers, where R' is an alkylene chain containing from 3 to 12 carbon atoms, which chain may be interrupted by one or more hetero-atoms and/or aromatic rings and may contain one or more carbon-carbon double or triple bonds, and each X is independently selected from O, S, or N; except that in a compound of formula Ia when A is a single bond, then R2 is not CH=CH(CONH2) or CH=CH(CONMe2). Other related compounds are also disclosed.