Preparation method of 2,2'-(4,4'-distylyl) dibenzoxazole by adopting new sulphur method

Abstract

The invention relates to a preparation method of 2,2'-(4,4'-distylyl) dibenzoxazole by adopting a new sulphur method. The preparation method is characterized in that methyl benzoic acid and ortho-aminophenol are dissolved in solvent oil, and boric acid is taken as a catalyst, so as to generate 4-methyl benzoxazole taken as a raw material; in an oxidation condensation reaction process of 4-methyl benzoxazole, an aprotic organic solvent is adopted for replacing sulphur as a reaction medium, wherein the aprotic organic solvent is diphenyl ether, hexamethylphosphoric triamide or formamide, a reaction temperature is 190-230 DEG C, reaction time is controlled to be 3-4 hours, energy consumption is reduced, and reaction yield and product quality are improved as the salvation effect and using amount of sulphur are reduced; and besides, equipment investment is reduced, and solid waste is greatly reduced, so that the preparation method is a clean production technology. A fluorescent brightener OB-1 provided by the invention can be used in ingredients of plastics, chemical fibers and the like for whitening and brightening.

Description

technical field

[0001] The invention belongs to the field of preparation of chemical raw materials, in particular to a preparation method of a fluorescent whitening agent, in particular to a 2,2'-(4,4'-distyryl)bisbenzoxazole Preparation. Background technique

[0002] Fluorescent whitening agent OB-1, the chemical name is 2,2'-(4,4'-distyryl)bisbenzoxazole, which belongs to benzoxazole dispersed fluorescent whitening agent, it can absorb ultraviolet rays Then emit blue-violet fluorescence, which is superimposed with the yellow light emitted by the substrate that needs to be whitened to form white light, so that the product obtains white light, and at the same time increases the brightness of the product. It has stable performance, good high temperature resistance, and light resistance. , Chlorine bleaching resistance and migration resistance, it is widely used in whitening and brightening in plastics, chemical fiber, coatings and other industries. It is a high-grade ...

Images