Summary of the technology
Regarding the existing state of the technique, the electrochemical processes have characteristics which make them very adequate to be applied for the synthesis of organic compounds with industrial application. Here, oxidation processes occurs upon electrodes named anodes where the substance which must be oxidized loses its electrons on the anode without needing conventional oxidising agents. Therefore, contaminants derived from the use of conventional oxidising agents are not generated and hence, no need for the management of hazardous residues is applicable.
On the other hand, the electrochemical processes are developed under soft conditions (atmospheric pressure and room temperature) and clearly facilitate further processes of separation of one of the compounds of the reaction mixture.
Description of the technology
The research group of Applied Electrochemistry and Electrocatalysis of the University of Alicante has developed a stereoselective process for the electrochemical synthesis of 3-(2-propynoxy)-2-propenoic acid and/or mixtures of acetylenic compounds (the same acid and propargyl alcohol) through one step. This synthesis does not use permanganate as oxidising agent, avoids extreme conditions of reaction and minimises the residues management. The electrochemist group is looking for companies interested in acquiring this technology for commercial purposes or for establishing projects to adopt this technology to their needs.
The research group of Applied Electrochemistry and Electrocatalysis has developed a new process for the synthesis of 3-(2- propynoxy)-2-propenoic acid and/or mixture of the same acid and propargyl alcohol through one electrosynthetic step by using an electrochemical device (electrochemical reactor, electrochemical cell, electrosynthetic cell, etc.). The electrochemical device, in which the synthesis is performed, includes a cathode, an anode of a material which contains nickel and a separator or ionic exchange membrane. The electrosynthetic process consists of the following stages: 1. Conversion of the nickel surface present in the anode to species of nickel (III) via a first electrolysis using aqueous solutions of alkaline metal hydroxide, where the anode of the electrolysis cell is nickel or a material containing nickel. At this stage, the anode is subjected to an electrochemical cycling pre-treatment. 2. Synthesis of 3-(2-propynoxy)-2-propenoic acid and/or mixtures of the same acid and propargyl alcohol by subjecting an aqueous solution of alkaline metal hydroxide and propargyl alcohol to a second electrolysis. At this stage, it is necessary to add propargyl alcohol until an established concentration. The temperature is around 25 ºC and the electrochemical device is the same as stated above at the first stage. This second electrolysis is performed at controlled potential (potentiostatic mode) or controlled current density (galvanostatic mode). 3. Acidification of the obtained reaction mixture from the previous stage of electrolysis with diluted mineral acids. At this stage, it is necessary to subject the reaction mixture from the electrolysis to an acidification process with diluted mineral acids, i.e. sulphuric acid or hydrochloric acid to give rise to the mixture of acetylenic compounds. Additional work up of the reaction mixture can be performed for the isolation of Z isomer of 3-(2-propynoxy)-2-propenoic acid via liquid–liquid extraction process using a polar organic solvent as ethyl acetate or ethyl ether.
Main advantages of its use
- Electrochemical process which oxidises propargyl alcohol to 3-(2-propynoxy)-2-propenoic acid via one reaction step.
- It provides mixtures of 3-(2-propynoxy)-2-propenoic acid and propargyl alcohol.
- The management of residues such as manganese dioxide or manganese coming from a chemical oxidising agent is avoided.
- The process is stereoselective giving rise to Z isomer of 3-(2-propynoxy)-2-propenoic acid.
- The use of extreme reaction conditions is avoided.
- The use of permanganate as oxidising agent is discarded.
- Automotive industry.
- Chemical Industry.
- Metal-Mechanical industry.
- The 3-(2-propynoxy)-2-propenoic acid belongs to a family of acetylenic compounds which are used as additive in galvanic baths for nickel and nickel-iron electroplating.