GB785670A - Improvements in or relating to chemical compounds for use as x-ray diagnostic agentsand to processes for their preparation - Google Patents

Abstract

The invention comprises compounds of the formula <FORM:0785670/IV (a)/1> in which R is hydrogen or a lower (1-7C) aliphatic carboxylic acyl radical, n is 2 or 3, and lower (1-7C) alkyl esters and non-toxic salts thereof; and a process of producing them by iodinating the isophthalic acid containing the NH2 group which may be acylated at an intermediate stage or as a final step. The iodination may be in stages with intermediate isolation of the mono-and di-iodo-products. In examples, the preparation of mono-, di-, and tri-iodo-5-aminoisophthalic acid using iodine monochloride on the amino acid, is described; the di- and triiodo products may be acylated with acetic anhydride, formic acid, caproyl chloride and other aliphatic acylating agents; the sodium, ethanolamine, and methylglucamine-salts and the diethyl ester of the tri-iodo-5-acetylamino-isophthalic acid are also made by customary methods.ALSO:The 5 - acylamino - 2 : 4 : 6 - triiodo - isophthalic acid salts and esters (see Group IV (b)) are used as X-ray contrast media. The 5-acetylamino - 2 : 4 : 6 - triiodo isophthalic acid sodium, diethanolamine, glucamine and other non-toxic salts in 50 per cent aqueous solution, insoluble salts, and suspensions, tablets and capsules for oral administration, are referred to. The formyl- and propionyl-amino derivatives are also referred to. Esters, e.g. the ethyl ester, of the acids may be used in oil solution or suspension and in compositions with methyl cellulose, gelatin, dextran and other thickening agents. The compounds are also useful for X-ray visualization of other structures than human organs.