The Optimal Green Technology For The Synthesis Of ?-hydroxyethyl Sulfone Sulfate Intermediates For Reactive Dyes

In recent years,study on of reactive dyes has gradually become a hot spot in dyestuff industry.Some mature technologies producing reactive dyes still have many shortcomings.For example:the synthesis of the intermediates and dyes will generate a lot of colored watsewater,and the low utilifor zation of the dyes,the low reactive dye fixation and the insufficient color fastness etc.These will eventually lead to a series of ecological problems of environmental pollution and atom economy.However,the high fixation rate is the top issue of reactive dyes which can save dyes and reduce pollution.It has become a major research trend.The aim of this paper is to synthesize a new reactive intermediates,which has improved water solubility and is easy to be combined with the dye parents for wide and practical application.All these will improve the utilization and fixation rate of the dyes.The structures of the synthesized compounds are characterized by 1H NMR,13C NMR,and FT-IR spectra.What's more,the optimal conditions and a green economy route for the synthesis will be explored to get high yield in order to meet the requirements of the contemporary production process.The main research contents are as follows:1.Synthesis of compound 5,?-hydroxyethyl sulfone sulfate intermediates for reactive dyes.By the reaction between P-mercaptoethanol and 2-chloroethylamine hydrochloride under the alkaline condition,the thioether-based compound 1 can be obtained.The amidition reaction of 1 with p-nitrobenzoyl chloride under the ice-cooling condition afforded compound 2 in about 90%yield.Compound 3,was obtained by oxidation reaction of 2 under the acidic condition with hydrogen peroxide in up to 95%yield.Amine compound 4 was obtained by either the use of hydrazine hydrate and Raney nickel or Raney nickel and hydrogen,the former giving a yield above 80%,while the latter close to 100%.The final intermediates compound 5 can be obtained when the compound 4 is heated with the concentrated sulfuric acid,which has a ivory white appearance and its amino value is 94.6%,the value of esterification is 94.3%as well as the reaction yield is about 96%.The total yield of the overall synthetic route when Raney nickel and hydrogen were used for reduction reaches 82%.2.New reactive dyes were synthesized by using the intermediate 5 with the reactive dye parents.The new reactive dyes were compared with a number of well-known reactive dyes such as dark dyes like reactive black KN-B and reactive blue KN-B in their performances' testing.From the result of some reactive dyes' important properties,such as dye uptake,fixation,color yield,the reactive dyes obtained from intermediate compound 5 instead of the commonly used para-ester have a marked improvement and thus have a good prospect.