PROCESS FOR PREPARING 1,3-DIMETHYL-4-(2,4-DICHLOROBENZOYL)-5-PYRAZOLYL-4-TOLUENE SULFONATE

摘要

A process for preparing 1,3- dimethyl-4-(2,4-dichlorobenzoyl)-5- pyrazolyl -4-toluene sulfonate of formula (I) comprises (a) reacting 3- methyl-5-pyrazolone with 4-toluenesulfonyl chloride in an aqueous soln. by use of toluene to get 3- methyl-5-pyrazolyl-4-toluene sulfonate (II); (b) reacting (II) with dimethylsulfonate by use of basic sodium hydrocarbonate to get 1,3-dimethyl-5-pyrazolyl-4-toluene sulfonate (III); (c) reacting (III) with 1,3-dichlorobenzene and CCl4 in the presence of AlCl4 catalyst, hydrolyzing it and treating it with NaOH to get 1,3- dimethyl -4-(2,4-dichlorogenzoyl)-5-sodium oxypyrazole (IV); (d) reacting (IV) with 4- toluenesulfonyl chloride to get (I).