Contrast media for angiography

A compound of the formula:

• 21
• wherein:
• R1 is selected from the group consisting of alkyl and alkyl substituted with hydroxy or alkoxy;
• R2, R3 and R4 are each independently selected from the group consisting of hydrogen and alkyl;
• R5 and R6 are each independently selected from the group consisting of hydrogen, alkyl and hydroxyalky,
• n is from 1 to 3;
• Z is —A—NHCH3, or when R1 is hydroxy or alkoxy substituted alkyl and/or when R3 is loweralkyl, or Z is hydroxy-C2-5-alkylamino;
• A is:
• 22
• wherein
• R7 is H or alkyl;
• R8 is H, alkyl, or alkyl substituted by hydroxy or alkoxy;
• or together R7 and R8 form a propylene or hydroxypropylene ring;
• m is O or 1;
• R9 and R10 are each independently H or alkyl;
• or R9 and R10 together form C4-C8 alkylene which is unsubstituted or substituted from one to three times with alkyl or hydroxy;
• R11 is amino or guanidino;
• o is from two to six;
• or a physiologically acceptable salt thereof.