Study On New Technology For Tebuconazole Production

As a new triazole fungicide, tebuconazole is widely recognized. To produce more product types, the tebuconazole production technology is introduced. The process route A was selected first, but a lot of production problems appeared and product output and quality were not satisfactory. To solve the problems, the process route B was selected. The tebuconazole technology was studied according to the production capacity and product quality before and after process change in order to improve product output and quality and production cost in this paper.Solid ketene is produced from condensation reaction of p-chlorobenzaldehyde and pinacolone in methanol solvent in the presence of alkali as catalyst before crystallization and centrifugal separation. Pentanone is produced from ketene in methanol solvent in the presence of catalyst before press filtration, solvent removal, etc. Sulfonium salt is produced from dimethyl sulfate and dimethyl sulfide in the dimethylsulfoxide solvent. Epoxide is produced from sulfonium salt and pentanone in the presence of catalyst before extraction, water wash, solvent removal, etc. At last, coarse tebuconazole is produced from epoxide and triazole in N,N-dimethylformamide solvent in the presence of catalyst before vacuum filtration, solvent removal, dewatering, crystallization, etc. The purified tebuconazole with purity of95%can be produced from heating, separation, crystallization and vacuum filtration of coarse tebuconazole, cyclohexane and water.After the process route is changed, the followings are seen:Methanol is used instead of n-butanol in the condensation reaction to solve such problems as low purity of product, sticking to wall during crystallization, etc. Thiodiethylene glycol is used as co-catalyst in the hydrogenation step to enhance the product purity. Tetrachloroethane and petroleum ether are not used as extracting agent in the synthesis step any more. The product purity is adjusted in the purification step. Cyclohexane is used instead of methanol as solvent in the purification step to enhance the purification effect. The tebuconazole has purity as high as95%. The production cost is controlled to156,400Yuan/t.