| abstract |
ABSTRACT Heterocyclic Chelating Agents There are provided heterocyclic chelating agents particularly useful for the preparation of diagnostic and therapeutic agents for magnetic resonance imaging, scintigraphy, ultrasound imaging, radiotherapy and heavy metal detoxification, said agents being compounds of formula I (I) (wherein X represents a bond, an oxygen or sulphur atom or a group of formula CHR1 or NR3; each R1 which may be the same or different represents a hydrogen atom, a group of formula OR3 or NR3R3 or an alkyl or alkoxyalkyl group optionally substituted by a hydroxyl group or by a group of formula NR3R3 or CONR3R3; each R2 which may be the same or different represents a hydrogen atom or an alkyl or alkoxy group optionally substituted by a hydroxyl or alkoxy group; each R3 which may be the same or different represents a hydrogen atom, an optionally hydroxylated alkyl group or a group of formula CH2Y; Y represents a group of formula COZ, CON(OH)R4, POZ2 or SO2Z; Z represents a group of formula OR4, NR4R4 or where each R11 which may the same or different is a hydrogen atom, a hydroxyl group or an optionally hydroxylated alkyl group , s is 0, 1 or 2, and W is a group CHR11, NR11 or an oxygen atom; and each R4 which may be the same or different represents a hydrogen atom or an optionally mono- or poly hydroxylated alkyl, alkoxyalkyl or polyalkoxyalkyl group; with the provisos that where s is 0 then W is a CHR11 group and that where X represents a bond or a group CHR1 at least one group R1 or R2 represents other than a hydrogen atom or an unsubstituted alkyl group) and chelate complexes and salts thereof. |