| 摘要 |
1. A compound of the formula I see diagramm : EP0062608,P12,F5 in which X is bromine or iodine, R1 is hydrogen or C1-6 alkyl or a non-chromophoric esterified carboxyl group, R2 is C1-6 alkyl which is unsubstituted or substituted by non-chromophoric groups, or is C2-4 alkenyl which is substituted by non-chromophoric groups, or is phenyl or phenyl which is substituted by fluorine, chlorine, C1-4 alkoxy, C2-6 alkoxyalkoxy, di(C1-4 alkyl)amino or C1-4 alkoxycarbonyl, or is a non-chromophoric substituent of the second order, and R3 is hydrogen or C1-6 alkyl which is unsubstituted or substituted by non-chromophoric groups or is C2-4 alkenyl which is substituted by non-chromophoric groups. |
