Process for the preparation of a iodinating agent

Patent metadata

Field	Value
Publication number	US-9157156-B2
Application number	US-201013375797-A
Country	US
Kind code	B2
Filing date	Jul 6, 2010
Priority date	Jul 7, 2009
Publication date	Oct 13, 2015
Grant date	Oct 13, 2015

Abstract

The present invention describes a process for the synthesis of a iodinating agent, being said iodinating agent iodine chloride (ICI.) In particular, the present invention relates to a process for the electrochemical preparation of ICI, as a useful iodinating agent in the preparation of iodinated organic compounds for use as contrast agents or their precursors in the synthesis of the same.

First claim

The invention claimed is:

1. A process for the electrochemical preparation of ICl comprising the steps of:
a. electrochemically oxidizing 1 mole of starting ICl in acidic aqueous solution, to give ICl 3 wherein iodine has an oxidation state equal to (III);
b. reacting said ICl 3 with iodine; and
c. obtaining 3 moles of ICl.

2. The process according to claim 1 , wherein said electrochemical oxidation is carried out in an electrolytic cell wherein the anodic and cathodic compartments are separated by a ion permeable membrane.

3. The process according to claim 2 , wherein the membrane is selectively permeable to anions or cations.

4. The process according to claim 2 , wherein the electrode of the cathodic compartment is made of graphite.

5. The process according to claim 2 , wherein the electrode of the anodic compartment is made of: platinum, graphite, modified graphite or glassy carbon.

6. The process according to claim 1 , in the presence of a cathode solvent system comprising: a strong acid mixed with water, a C 1 -C 4 alcohol or mixture thereof.

7. The process according to claim 6 , wherein said strong acid is hydrochloric acid or sulphuric acid.

8. The process according to claim 6 , wherein said cathode solvent system comprises a mixture of water and hydrochloric acid.

9. The process according to claim 8 , wherein said hydrochloric acid has a concentration comprised from 5% to 40% by weight.

10. The process according to claim 1 , wherein the starting ICl in the acidic aqueous solution has a concentration comprised from 15% to 40% by weight.

11. The process according to claim 1 , wherein a part of the produced ICl is re-introduced as a starting reagent in the anodic compartment.

12. The process according claim 1 , wherein the electrochemical oxidation is carried out in galvanostatic or potentiostatic mode, operating at values of current density comprised from 50 to 150 mA/cm −2 .

13. The process according to claim 1 , comprising transferring the solution obtained in step-a into a separate reactor, before carrying out the next step-b.

14. The process according to any one of claim 1 , 5 , 6 or 11 further comprising iodinating a compound of formula (I)

wherein:
R is —N(R′) 2 or —OH;
R1 is independently in each occurrence —COOR′, —CON(R′) 2 ; and
R′ is independently in each occurrence hydrogen or (C1-C4) linear or branched alkyl optionally substituted by one or more hydroxy groups present as such or in a protected form, to obtain a compound of formula (II)

15. The process according to claim 14 wherein:
R is a hydroxy —OH or amino group —NH 2 and the groups R1 are the same and are selected from the group consisting of —COOH and —CONHR′, wherein R′ is selected from the group consisting of —CH(CH 2 OH) 2 and —CH 2 (CHOH)CH 2 OH.

16. The process according to claim 5 , in the presence of a cathode solvent system comprising: a strong acid mixed with water, a C 1 -C 4 alcohol or mixture thereof.

17. The process according to claim 10 , wherein a part of the produced ICl is re-introduced as a starting reagent in the anodic compartment.

Assignees

• Anelli Pier Lucio
• Viscardi Carlo Felice
• Delogu Pietro
• Goffredi Fabrizio
• Nardelli Alfonso
• Giovenzana Giovanni Battista
• Bracco Imaging Spa

Inventors

• Anelli Pier Lucio
• Viscardi Carlo Felice
• Delogu Pietro
• Goffredi Fabrizio
• Nardelli Alfonso
• Giovenzana Giovanni Battista

Classifications

• C25B1/24 Primary

  Halogens or compounds thereof · CPC title

• C07C227/16

  by reactions not involving the amino or carboxyl groups · CPC title

• C07C231/12

  by reactions not involving the formation of carboxamide groups · CPC title

• C07C67/00

  Preparation of carboxylic acid esters · CPC title

• C07C235/48

  having the nitrogen atom of at least one of the carboxamide groups bound to an acyclic carbon atom of a hydrocarbon radical substituted by singly-bound oxygen atoms · CPC title