PROCESS FOR THE PREPARATION OF 5-ACYLAMINO-2,4,6- TRIIODO-OR TRIBROMO-BENZOIC ACID DERIVATIVES AND CORRESPONDING NOVEL 5-ACYLAMINO-2,4,6-TRIIODO OR TRIBROMO-BENZOIC ACID DERIVATIVES OBTAINED BY SAID PROCESS

A PROCESS FOR THE PREPARATION OF 5-ACYLAMINO-2,4,6-TRI-IODO- OR TRIBROMO-BENZOIC ACID DERIVATIVES AND CORRESPONDING NOVEL 5-ACYLAMINO-2,4,6-TRIIODO OR TRIBROMO-BENZOIC ACID DERIVATIVES OBTAINED BY SAID PROCESS. A process for the preparation of 5-acylamino-2,4,6-triiodo or tribromo-benzoic acid derivatives of formula I I, wherein: X is I or Br, R is H or a variously substituted alkyl, or a group of formula wherein X has the above meanings; Y is hydroxy, alkoxy, hydroxyalkoxy, alkylamino or hydroxyalkylamino; Z may be the same as COY or it is hydroxyalkylaminocarbonyl provided that at least one of the two acyl or R groups is hydroxy-substituted, which process comprises the rearrangement of the corresponding 5-(alkylaminocarbonyl-alkoxy)-2,4,6-triiodo or tribromobenzoic acid derivatives, in the presence of bases.