GB898781A - Triiodinated diamino-propionic acid derivatives and their use in x-ray contrast media - Google Patents

Abstract

The invention comprises tri-iodo-3,5-diaminophenylpropionic acids of the general formula <FORM:0898781/IV (b)/1> in which R is an aliphatic or cyclo-aliphatic hydrocarbon radical with 1 to 6 carbon atoms, esters thereof with alcohols containing 1 to 4 carbon atoms and non-toxic salts thereof with inorganic or organic bases, and a process for the preparation of such acids or esters wherein a corresponding a -alkyl- or -cycloalkyl-b -(3 : 5-diaminophenyl)-propionic acid or ester is iodinated by methods known per se with optional hydrolysis of an ester group, if desired. The iodination may be carried out by means of iodine monochloride in hydrochloric acid solution or potassium iodide dichloride in neutral or weakly hydrochloric acid solution. Cycloaliphatic groups specified include cyclopentyl and cyclohexyl groups. An example is furnished. The sodium and methyl glucamine salts are described. The products are employed in X-ray contrast media (see Group VI). 3 : 5 - Diaminophenyl - alkyl - or - cycloalkyl propionic acids are produced by introducing the desired a -aliphatic or cycloaliphatic substituent into 3 : 5-dinitrobenzoyl acetic acid ethyl ester, hydrogenating the product to obtain the b -3 : 5-diaminophenyl-b -hydroxy-a -alkyl or -cycloalkyl propionic acid ester, replacing the hydroxy group with a chlorine atom by means of thionyl chloride and hydrogenating the product to replace the chlorine atom by hydrogen.ALSO:X-ray contrast media comprise compounds of the general formula <FORM:0898781/VI/1> in which R is an aliphatic or cycloaliphatic radical with 1-6 carbon atoms, esters thereof with alcohols containing 1-4 carbon atoms or their non-toxic salts with inorganic or organic bases (see Group IV (b)) and a carrier material. The sodium and methylglucamine salts are referred to. Tablets are prepared from a composition obtained by mixing a -ethyl-b -(3 : 5-di-amino-2 : 4 : 6-triodophenyl) propionic acid with maize starch paste, drying under vacuum, granulating and mixing with maize starch and magnesium stearate, dragees are prepared by coating the granulated material described above with sugar syrup and waxing the product, gelatine capsules are prepared containing the sodium salt of the above acid in admixture with maize germ oil, soya lecithin and coconut fat.