Process for the monotopic preparation of intermediate organo-iodinated compounds for the synthesis of ioversol

A process for preparing an organo-iodinated compound, comprising the following steps:a) acylating 2,4,6-triiodo-5-aminoisophthalic acid of formula (A) below:to obtain an intermediate compound Ya;b) chlorinating the intermediate compound Ya to obtain an organo-iodinated intermediate compound Yb;c) amidating the organo-iodinated intermediate compound Yb to obtain an intermediate compound Yc; andd) deprotecting the intermediate compound Yc, the steps a), b), c) and d) being carried out without isolation of at least one intermediate compound chosen from Ya and Yc.