Preparation Of Amino C Acid By Selenium-Catalyzed CO/H₂O System

Amino C acid?3-amino-1,5-naphthalenedisulfonic acid?and molecular formula is C₁₀H₉NO₆S₂.It is white crystal,soluble in water with blue fluorescence.Amino C acid is an important intermediate for the synthesis of direct dyes and reactive dyes.With the development of economy and society,the demand for direct dyes and reactive dyes is increasing.Nowadays,most enterprises use catalytic hydrogenation reduction method and iron powder reduction method to prepare amino C acid,iron powder reduction method produces a large amount of iron slag and waste water in the production process,which pollutes the environment;the catalytic hydrogenation reduction method has certain restrictions in industrial production because of the high cost.Therefore,it is of great significance to find a new reduction method with low cost and low environmental pollutio n.This thesis is inspired by the study of the reduction of Se/CO/H₂O system to prepare amino compounds,under the condition of high temperature and high pressure,using water as solvent,amino C acid was prepared by the reduction of Se/CO/H₂O system.DMF is the solvent of the reaction,and the atmospheric pressure of the reaction is realized.Based on the previous work a nd the data of this experiment,the mechanism of the reaction is deduced,as a reducing substance,H₂Se could reduce aromatic nitro compounds to aromatic amines,after the reaction,H₂Se was oxidized to Se and precipitated out of the reaction system.This method has the advantages of being easy to recycle catalyst,low cost and small pollution to environment,which is in line with the requirements of green development.Through a series of experiments,this thesis determined the optimal conditions for the reaction:1?high pressure experiment:nitro compound 2.0 g?4.0 mmol?;Se 0.0269 g?0.34 mmol?;H₂O 30 mL;NaOH 0.054 g;P_CO 4.0 MPa;Na₂CO₃ 0.9 g;T160?;t 3 h;the yield of amino C acid was up to 98.0%.The order of influence of various factors on the reaction is:reaction temperature>the amount of selenium>the amount of water>CO gas pressure.2?atmospheric pressure experiment:nitro compound 1.5g?3.0 mmol?;Se0.01975g?0.25 mmol?;NaOH 0.0405 g;NaOAc 4 mmol;H₂O 2 mL;DMF 40 mL?dehydration?;T 95?;t 5 h;the yield of amino C acid was up to 86.5%.The order of influence of various factors on the reaction is:reaction temperature>the amount of selenium>the amount of water>the amount of solvent.