Study On The Synthesis Of Prothioconazole

1.The method for 2-chloro-1-(1-chlorocyclopropyl)ethanone using ?-acetyl-?-butyrolactone as raw material was developed by evaluating several procedures for prothioconazole.Then triazoloxanone was synthesized using 2-(1-chlorocyclopropyl)-3-chloro-1-(2-chlorophenyl)-2-propanol,hydrazine hydrate,acetone and thiocyanate as the raw materials by the cyclization reaction,and was converted to the prothioconazole in the presence of formic acid.The overall yield is over 35%.2.On the base of a comprehensive evaluating of the current process which has some problems in the synthesis of an important intermediate 2-chloro-1-(1-chlorocyclopropyl)ethanone such as the low yield,poor materials and difficulty for control,the details of process are systematically investigated and optimized.Finally,an optimized synthetic process with high operability,mild reaction conditions,high yield,and high potential to industrial production was provided.3.The process conditions of 2-(1-chlorocyclopropyl)-3-chloro-1-(2-chlorophenyl)-2-propanol were explored and optimized to avoid the traditional Grignard solvent ether which has flammable and explosive properties.A new type of mixed solvent,which is more stable,initiate easily,and has strong solubility for Grignard reagents,was screened out,providing a new solvent choice for the synthesis of special Grignard reagents.4.The new method was established for the synthesis of triazolidinone using hydrazine,acetone and thiocyanate as the raw material.The problems of separating and purifying of the intermediates were resolved,and the lowed cyclization yield was improved.5.The process for prothioconazole was optimized.By-products were suppressed greatly,and the yield was improved.By changing the reaction solvent and reaction concentration,the yield of this step was increased from 50% to 85%.It has a good industrial application prospects.