| 摘要 |
P-iodophenoxyacetic acid drug intermediates p-lodophenol synthesis method, comprising the following steps: equipped with a stirrer, a thermometer, a dropping funnel, the reaction flask was added water that temperature is 2-6'C, 80-100 mL sulfate solution was slowly added, 1.5mol p-aminophenol was addedin batches, stirring to dissolve, cooled to 5--10 C, 1.5mol potassium nitrite was dropwise added to 200mol aqueous solution, the duration of dropping process was 30--40min, KI test paper measuring end of the reaction, maintain the stirring rate at 300-500rpm for 10min, generating diazonium salt solution(3), and 30 mL concentrated phosphoric acid was added into the solution; 300mL aqueous solution, 1.5-2mol sodium iodide was added to another reaction vessel, cooled to 3--8 C after the dissolution, diazonium salt solution resulting was slowly added when maintaining a low speed rate of 100rpm, 2g metal powder was added after 10min, maintaining the solution temperature at 85-90 C, until the reaction no longer release any nitrogen, oil occurs, the solution was cooled to 20-30C, when it was extracted with the organic solvent, then the resultant extract washed with reducing solution and saline solution, the resulting solution was evaporated under reduced pressure to collect a fraction 120--135C, distillate recrystallized in the methyl ether, ultimately got p-lodophenol. |
