Decabde Catalytic Synthesis And Purification Processes And Process Conditions To Optimize The Synthesis Study B-ethyl Parathion Preliminary Study

This paper studied two new processes for catalytic synthesis of decabromodiphenyl ether which were carried out distinguishingly by brominating diphenyl oxide with bromine and bromine chloride in the presence of a novel metal catalyst. Uniform test design and simplex optimization were applied in the research, by which the optimum reaction conditions were obtained. And a new method of DBDPO purification was developed.The research demonstrated that the novel metal catalyst had an excellent catalytic performance, such as high catalytic activity, high catalytic selectivity compared to those of traditional ones such as aluminum trichloride and aluminum tribromide which were deliquescent, hygroscopic and unstoragible. Studies showed that the novel metal catalyst was more convenient to be used. As a brominating agent, bromine chloride had higher catalytic activity and selectivity than bromine. Furthermore, the utilization efficiency of bromine was improved by using bromine chloride because the by product was hydrochlgride not hydrobromide.The influential factors of brominating reaction were investigated by uniform test and the optimum process conditions were obtained by simplex optimization as follows:The optimum reaction conditions for catalytic synthesis of DBDPO by brominating diphenyl oxide with bromine chloride followed as: molar ratio of diphenyl ether to bromine chloride was 1:13, ratio of metal catalyst to diphenyl oxide was l:10(w/w), diphenyl ether feeding temperature 12 and reflux time 7.2 hours, the yield of purified DBDPO was up to 97.1%.The optimum reaction conditions of catalytic synthesis of DBDPO by brominating diphenyl oxide with bromine followed as: molar ratio of diphenyl ether to bromine was 1:30, ratio of metal catalyst to diphenyl oxide was l:5(w/w), diphenyl ether feeding temperature 30, ratio of dichloromethane to dipheny oxide was 5:l(v/v) and reflux time 5.5hours, the yield of purified DBDPO was up to 95.2%.A simple and convenient DBDPO purification method which applied xylene as solvent after DBDPO had been washed with chloroform was developed. Then the free bromine in the solution reacted with an alkali aqueous solution. The resulting solution was separated and the uper solution was distilled under a reduced pressure to remove its solvent. Thus the white purified DBDPO was obtained with the bromine content 83.1%, mp: 304-309.