Synthesis Of 2,6-dichlorobenzoxazole

2,6-dichlorobenzoxazole is a valuable organic intermediate product in synthesizing plant protection ,for example for manufacture of active compounds for herbicides . This article study on the synthesis of 2,6-dichlorobenzoxazole that is precursor of Fenoxaprop-ethyl by using our prepared benzoxazolin-2-one and 6-chlorobenzoxazolin-2-one products. This article emphasizes on the synthesis of three intermediate products and optimize of key factors:First is the synthesis of benzoxazolin-2-one by the reaction of 2-aminophenol and urea in inert organic solvent. We discover better reaction condition through single factor and orthogonal experiment observe and study. Reaction yield is up to 89%, the high degree of the product purity is obtained. We ensure that the product is our target by IR detecting.Second is the synthesis of 6-chlorobenzoxazolin-2-one, which is obtained by the chlorination of benzoxazolin-2-one and sulfuryl chloride in suitable organic solvent. We successfully find the chlorination is very perfectibility and selectivity in this reaction. We discover better reaction condition through single factor and orthogonal experiment observe and study. Purity of the product is satisfactory by recrystallization, yield is up to 89%. We can make sure the product is 6-chlobenzoxazolin-2-one by IR detecting.Third is the synthesis of 2,6-dichlorobenzoxazole, whose products are obtained by excess PCI₅ chlorination in suitable solvents. The excess PCI₅ crystallises is filtered off with suction and the filtrate is distilled under reduced pressure. We discover better reaction condition through single factor observe and study. The product yield of chlorination is up to 60%, and Purity is acceptable by distillation. The product is detected by IR.In this article, we bring forward the new technological route of synthesis of 2,6-dichlorobenzoxazole by facilitated raw materials, especially preparing high purity 6-chlobenzoxazolin-2-one intermediate product is obtained selectively and blandly.There has innovation in technology and it is economical.