From Voltammetry to Industrial Plant: Electrochemical Synthesis of DL-Homocysteine from DL-Homocystine — An Example of Scale-Up

Abstract

An industrial process for the electrochemical synthesis of DL-Homocysteine from DL-Homocystine is described. DL-Homocysteine is a key intermediate for the synthesis of Citiolone (a powerful agent used to treat bronchitis and nasal catarrh). The work starts with a fundamental study, the voltammetric behaviour of DL-Homocystine, followed by a laboratory and pilot plant study and finishes with the development of an industrial process (30 tons/year of DL-Homocistine electroreduced). The method avoids the use of hazardous and polluting reductants such as Zn/H⁺. The figures of merit are a material yield of 95%, production over 200kg/m²day and a energy cost less than 2 kWh/kg.