CHELATING COMPOUNDS

摘要

The invention provides novel condensed macrocylic chelants of formula [X(CR<2>R<3>)n]m, (wherein each X independently represents an oxygen or sulphur atom or a group of formula NH, N(CR<2>R<3>)pR<4>, N(CR<2>R<3>)pY, or N(CR<2>R<3>)n-N((CR<2>R<3>)pY)2; each Y independently represents a group COZ, SO2Z, POZ2, CON(OH)R<2>, CH2SR<2>, CS2R<2> or CSZ; each Z independently represents a group OR<2> or NR<2>R<2>; n is an integer of 1 to 4; m is an integer of 3 to 8; p is an integer of 1 to 3; each R<2> independently represents a hydrogen atom or a C1-8 alkyl group optionally mono- or poly- substituted by hydroxyl or C1-8 alkoxy groups and at least one pair of R<2> groups, in each pair one being from a (CR<2>R<3>)n moiety and the other being from a (CR<2>R<3>)n or (CR<2>R<3>)p moiety, together with the intervening atoms represents a 5 to 8 membered, saturated fused ring optionally containing one or more ring heteroatoms selected from nitrogen, oxygen and sulphur, said fused ring optionally being substituted by a group R<1>; each R<1> independently represents a group R<4> or a nitrogen-attached group (CR<2>R<3>)pY; each R<3> independently represents a hydrogen atom or a C1-8 alkyl or C1-8 alkoxy group optionally mono or poly substituted by hydroxy or C1-8 alkoxy groups; and each R<4> independently represents a hydrogen atom, a halogen atom or a hydroxyl group or an optionally mono- or poly-hydroxylated C1-8 alkyl, C1-8 alkoxy, (C1-8 alkoxy)- C1-8 alkyl or poly- (C1-8 alkoxy)- C1-8 alkyl group, a sulphonate group or a group (CR<2>R<3>)pY; with the proviso that at least 2 Y groups are present). These chelants are useful in the preparation of diagnostic and therapeutic agents, in particular chelate complexes suitable for use as contrast agents for diagnostic imaging techniques, e.g. MRI.