3,5-DICHLORO-6-PHENYLPYRIDAZINE synthesis

Yield: 95.3%

Reaction Conditions:

with phosphorus pentachloride;trichlorophosphate at 90 - 110; for 4.5 h;Molecular sieve;

Steps:

4 Example 4
Addition of 68.9 g of 6-phenyl-3-pyridazinone g (0.4 mol) in a 500 ml four-neck flask, prepared in Example 1Modified ZSM-5 molecular sieve 7 g, 413.4 g of phosphorus oxychloride and 166.5 g of phosphorus pentachloride (0.8 mol), and then heated to 90°C, and kept warmAfter half an hour of reaction, the temperature was raised to 110°C and the reaction was refluxed for 4 hours. The reaction was completed. HPLC was used to determine the area normalized to give 3-phenyl-4-one.The ratio of chloropyridazine, 3-phenyl-4-6-dichloropyridazine, 3-phenyl-4-5-dichloropyridazine was 0.5:98.4:1.1;The reaction solution was distilled under reduced pressure to remove phosphorus oxychloride, and the temperature under vacuum distillation was 120°C. The degree of vacuum was -0.098 MPa;After being bundled, it is cooled to room temperature, then 137.8g of toluene is added, stirred and heated to recrystallize, the Buchner funnel is filtered, and the wet product is blownThe box was dried at 80°C for 8 hours to obtain 86.5 g of a white solid-like 3-phenyl-4-6-dichloropyridazine product (HPLC: 99.7%; Yield:95.3%).

References:

Changzhou Woteng Chemical Technology Co., Ltd.;Wan Zhibing;Wang Zhichao;Sun Kezhou;Liu Rong CN106831600, 2017, A Location in patent:Paragraph 0010; 0011; 0012