The present invention discloses a process for the preparation of
Iopamidol of formula (II) and comprising the following steps: a) reacting the Compound (I) wherein X is OR2 or R3, and wherein R2 and R3 are a Ci-C6 linear or branched
alkyl, C3-C6 cycloalkyl, C6
aryl, optionally substituted with a group selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, t-butyl and phenyl, with the acylating agent (S)-2-(acetyloxy)
propanoyl chloride in a reaction medium to provide the acetyloxy derivative of Compound (I); b) hydrolyzing the intermediate from step a) with an
aqueous solution at a pH comprised from 0 to 7, by adding water or a diluted alkaline solution such as
sodium hydroxide or
potassium hydroxide, freeing the hydroxyls from the
boron-containing protective groups, obtaining the N—(S)-2-(acetyloxy)propanoyl derivative of Compound (II); c)
alkaline hydrolysis to restore the (S)-2-(hydroxy)propanoyl group and to obtain
Iopamidol (II) and optional
recovery of the
boron derivative from the solution obtained in step b). The
boron-containing protective group is versatile, efficient and recyclable. A one-pot synthesis, without intermediate isolation is provided, leading to a decreasing of recovered and recycled solvents and a significant increasing in the yield, representing a significant
advantage in terms of cost-effectiveness of the entire process and environmental awareness.