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D-phenylalanine as an important chemical pharmaceutical raw materials, with a wide range of uses. Comprehensive overview of the nature of the D-phenylalanine, use and preparation of development profiles; process improvement on the basis of the enzyme acid Preparation of D-phenylalanine, and research and development of a national initiative reaction separation coupled Preparation of D-phenylalanine new technology; investigated by a large number of experiments, to verify the feasibility and advantage of the technology. The main content of this paper and innovations include: the intermediate prepared by enzymatic conversion of N-carbamoyl-D-phenylalanine. D, L-BH (D, L-benzyl hydantoin) as the raw material through the D-hydantoin enzyme converted to N-carbamyl-D-phenylalanine. Experiments demonstrated in D, L-BH concentration 20g / L, bacteria mud and D, L-BH mass ratio of 1:1, pH9.5 and temperature 38 ° C case, the D-hydantoin enzyme D, L-BH has a high catalytic activity, the yield of N-carbamyl-D-phenylalanine is more than 80%; small number of intermittent feeding enables more rapid enzymatic conversion reaction, D, L-BH conversion rate stable at between 60-70%, the bacterial sludge and D, L-BH actual mass ratio of 1:2.5, to improve the utilization of the enzyme, reducing the cost. Nitrous acid hydrolysis of N-carbamyl-D-phenyl alanine Preparation of D-phenylalanine. Nitrous acid hydrolysis using hydrochloric acid and sodium nitrite, the reaction of N-amino carboxamido-D-phenyl alanine Preparation of D-phenylalanine obtained by experiment with a more reasonable reaction conditions: sodium nitrite and N-carbamoyl acyloxy-D-phenylalanine molar ratio is 1.2:1, and the sodium nitrite solution dropwise acceleration control 10mL/min about the optimum reaction time was 3 hours, the temperature at about 15 ℃; choice of a strongly acidic cation resin on the product D-phenylalanine, separation and purification, to optimize separation conditions; product D-phenylalanine yields above 80%. The first reaction separation coupled Preparation of D-phenylalanine new technology. Alternative hydrochloric acid to provide the acidic environment of the reaction system required use of a strongly acidic cation exchange resin, on the one hand, to avoid the salt formation of byproducts; other hand, the adsorption and separation of the reaction product of D-phenylalanine, so that the reaction and separation coupling, simplifying the process, reducing production costs. The overall yield more than 70% using this method of preparation of D-phenylalanine. The study of the country have no relevant reports, and innovative.
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