Dazoxiben drug intermediates 4- (2-chloroethoxy) benzoic acid synthesis method

摘要

#$%^&*AU2016102265A420170223.pdf#####ABSTRACT Dazoxiben drug intermediates 4- (2-chloroethoxy) benzoic acid synthesis method, comprising the following steps: equipped with a stirrer, thermometer and reflux condenser, the reaction vessel was added 0.31mol methylparaben (2), 300ml potassium sulfite solution, 0.36-0.39mol 1- amine-2-chloroethane (3), 0.53mol cuprous chloride, raised the solution temperature to 70 - 75 C, controlled mixing time for 13-15h, reducing the temperature of the solution to 10 - 15 C, added oxalic acid solution to adjust pH to 3-4, separated the organic layer, the aqueous layer was extracted with propionitrile solution, combined organic layers, washed with saline solution, dehydrated with dehydrating agent, the solvent was distilled off under reduced pressure, the precipitated solid was washed with toluene solution, recrystallized from nitromethane solution, got crystals of 4- (2-chloroethoxy) benzoic acid .