NEW MATERIAL: Ligands represented by formula I [R1 is a group represented by formula II (R6 is alkyl, etc.; R7 is H or alkyl, etc.; and m is 0 or 1); R2-R4 are each a group represented by formula III (R8 and R9 are each H, alkyl, etc.); R5 is H, alkyl, hydroxyalkyl, etc.); R10-R13 are OH or a group represented by formula IV (R14 and R15 are each H or alkyl, etc.; and at least one of R10-R13 is a group represented by formula IV] and their salts.
EXAMPLE: Monopropionamide of 2-methyl-1,4,7,10-tetraazacyclododecane-N,N',N", N"'-tetraazacyclododecane-N,N'-N",N"'-tetraacetic acid.
USE: A starting material for a magnetic resonance imaging agent, an X-ray contrast agent, a chemical shift reagent, etc. A complex is formed by lanthanide ions, transition metal ions, metal ions having atomic numbers 55, 56, 82 and 83 and ligands represented by the formula I.
PROCESS: A compd. represented by formula V and amine represented by formula VI are reacted to obtain the compd. represented by the formula I.
PARI DOMINIKU
MEE DOMINIKU
DOUSE DEIDEIE
