The Study Of L- Amino Propanol Electroanalysis Synthesis By L-alanine

L-amino propanol is an important raw material, intermediates and chiral auxilaries in the pharmaceutical and agricultural industry, especially as the third generation of synthetic broad-spectrum antibiotics levofloxacin quinolones important intermediate, In asymmetric synthesis as chiral auxiliaries have great purposes.Therefore, the market demand is gradually increasing in recent years. The synthesis of traditional is more complex, high production costs and more polluting. So it has an important significance to work out cheap and easy synthesis and L-amino alcohol testing methods, it will provide the basis for industrial production. In this paper, we use the electrolytic method for the synthesis of L-amino propanol, direct reduction of L-alanine. Break through the traditional chemical synthesis method, it has many advantages, for example, with mild reaction conditions, no toxic chemicals, easy to control, the production process produces no waste and so on. During the reaction we use self-made cell which is separated by the cation membrane, deionized water as solvent, use Ru/C as the catalyst. During the electrolytic hydrogenation reaction, we studied on effects of these factors on the conversion of the raw material, for example, electrolyte concentration of the cathode and anolyte, supporting electrolyte, electrolysis voltage, temperature, electrolysis time, the cation exchange membrane, catalyst type and amount of and so on. Meanwhile, the product of the electrolyte purification methods has been systematically studied, the results were that, first the electrolyte solution concentrated by vacuum, purified with methanol, finally, vacuum distillatied the solvent, we got the L-amino propanol. We established the qualitative and quantitative methods by TLC and HPLC to analysis the product.By optimizing the reaction conditions, we obtained the optimal conditions for electrochemical synthesis of L-amino alcohol. The anode with 0.5mol/L L-alanine solution, 2.45g support electrolyte NaCl,2.5mL sulfuric acid, Ru/C catalyst was 0.3g. For anode, the concentration of sulfuric acid was 6.5%(by volume). The result we that the convesion rate of L-alanine was 87.6%, wit h voltage of 14V, temperature was 35～36℃, electrolysis time was 15h.We established the qualitative and quantitative methods by HPLC to analysis the product. The chromatographic conditions were:the column was Shimpack VP-ODS(150mm×4.6mm,5μm); the mobile phase was methanol-phosphate buffer solution, sodium dihydrogen phosphate concentration was 0.02mol/L, pH was 4.00 regulated by phosphate, the volume ratio of Methanol and phosphate was 30:70, the flow rate was 0.50mL/min, the detection wavelength was 222nm, column temperature was 30℃, injection volume was 2μl. The establishment of this method provided a reliable method for the company who product and use L-amino alcohols.