Preparation Of Chiral Alcohols By Microbial Transformation

This paper was prepared by microbial transformation(S)- N, N- two-hydroxy methyl-3-(2- thiophene)-1- propylamine [Abbreviate(S)-DHTP],which was a key intermediate during the synthesis of Duloxetine. In this study, a strain that was prepared by the conversion of DKTP to(S)-DHTP, was selected from the soil.And the bacterial strains were identified by morphological and physiological and biochemical identification, and the transformation conditions were optimized. On this basis, the-DHTP product was successfully prepared by vacuum distillation and crystallization purification method, which establish a transformation model containing thiophene group.Firstly, Similar to the substrate structure of acetophenone as the sole carbon source were used to select microorganisms. A efficient conversion of DKTP strains(e.e. % was above 90%) were got in anlaysising the conversion of liquid. The strains were identified preliminarily for saccharomyces cerevisiae by the method of morphological and physiological and biochemical experiments.Secondly, optimized the 17 strains of transformation conditions, mainly on the glucose, sucrose, auxiliary substrate selection and concentration of isopropyl alcohol to add, substrate concentration, reaction time, reaction temperature optimization experiment.Optimization transformation condition as fellows:the auxiliary substrate concentration of isopropyl alcohol was 25 g/L, the transformation of the substrate concentration was1.5 g/L, the temperature was 35 ℃, the reaction time was 24 h.By reduced pressure distillation unit to raise the transformation rate of strain of using vacuum pump can be generated by the acetone extraction, makes the substrate transfer reaction equation to move forward, to improve the product(S)- DHTP conversion rate of the conversion rate can reach 72.33%, compared to not in the device into the reaction of the conversion rate increased by 7.78%.Finally, using the method of crystallization resolution can improve the optical purity of the product, its enantiomer quantity can reach 99.68%Saccharomyces cerevisiae –bacteria 17 was established into the preparation of duloxetine hydrochloride intermediates of chiral alcohols(S)- DHTP biological transformation model, converting conditions as follows: the transformation of the substrate concentration was 1.5 g/L, auxiliary substrate concentration of isopropyl alcohol was add to 25 g/L, the temperature was 35 ℃, the reaction time was 24 h. Conversion of liquid was took out by 0.085 Mpa of vacuum distillation and was crytalized to obtain high yield, high optical purity of the product(yield > 70%, e.e. % > 99%).