| 摘要 |
Clofibrate drug intermediates p-chlorophenol synthesis method, comprising the following steps: equipped with a stirrer, a thermometer, a dropping funnel, a reaction vessel was added 700mL sodium chloride solution with a mass fraction of 60%-70%,2mol p-aminophenol was slowly added, stirred at a low rate until completely dissolved, the temperature of the solution was reduced to 8-12C, dripping 1.5-2mol potassium hydrogen sulfate in 200ml water, maintaining the temperature at 15-20C during the process, KI test paper measuring the end of the reaction, generating diazonium salt (3); the diazonium salt (3) generating in the step (i) was added to a 200mL concentrated potassium chloride solution containing 1.5mol chromous bromide, warmed to 120--130C, refluxed 30-40min, the solution is reduced to a temperature of 30--35C, the oil was separated and the aqueous layer extracted with a solvent, the solvent combined with the oil layer was distilled under reduced pressure to recover the solvent, collecting fractions of 110--125C, ultimately got p-chlorophenol. |
