Studies On Selenium-catalyzed Reduction Of DNS To DSD Acid

4,4'-Diaminostilbene-2,2'-disulfonie acid in fine chemicals is an important intermediates,hereinafter referred to DSD acid,mainly used as the manufacture of direct dyes?fluorescent whitening agent and moth-proofing agent.At present,the common method is iron powder reduction,electrochemical method,but all these methods caused serious environmental pollution,and wasting resource,which restricted the further development of DSD acid.In this paper,the Se/CO/H2O system is applied to DNS acid reduction,which is a new method of preparation of DSD acid,and more friendly to the environment and economical.Firstly,we did not to add any organic solvent,only with water as a reaction solvent in high temperature and high pressure conditions,using Se/CO/H2O system to reduction the DNS preparation of DSD acid.Then,through a lot of experiments,the reaction of the optimum experimental conditions are determined.This paper is divided into four parts.The first part is preface,which mainly introduces the DSD acid properties,structure,applications and industry production technology,and compare their advantages and disadvantages;The second part is the experimental section,which describes the experimental process and product analysis method;The third part is for the conditions of this experiment;The fourth part is a conclusion.This paper give the relatively better reaction conditions by experiments:DNS 1.5g?selenium 0.064g?potassium carbonate 0.10g?water 60ml?temperature 180 ??pressure 6 MPa?reaction time 4h.In this condition,The testing the products of amino value can reach more than 95%,the target product purity can be up to 98%,4,4'-Diaminodiphenylethane-2,2'-disulfonie acid about 0.5%and this color is light yellow.The DSD acid purity and benzyl material content basically reaching at present the provisions of the state industrial standard.