Study On Preparation Of (R)-(-)-2-Amino Propanol

Chiral amino propanol is an important kind of organic intermediate, which has been widely applied in synthesizing medicine, agrochemical, flavor and other organic compounds. In this thesis, (R)-(-)-2-alaninol was prepared indirectly and directly from (R)-(-)-2-amino acid as raw material, with borodydrides as reductive. Qualitative and quantitative analyses on the prepared product were performed using the GC-MS, conventional GC and chiral GC and polarimetry. The comparision between the indirect method, where (R)-(-)-2-amino acid firstly esterified with ethanol, the formed ester was reduced by sodium borohydride and the direct method, where (R)-(-)-2-amino acid was reduced directly with the in situ zinc borohydride,it was found that the latter method was a more efficient technological route, yield of the object product could reach to above 80%, the specific rotary value was -18.19o, and optical purity (e.e%) was 100%. Zinc borohydride was prepared by anhydrous zinc chloride and potassium borohydride in tetrahydrofuran, and the (R)-(-)-2-amino acid was reduced directly with the in situ formed zinc borohydride simultaneously. The direct method could simplify the preparation step of (R)-(-)-2-amino propanol,avoid the separation of enantiomers, and decrease the product cost ,thus was of industrial application prospect.