933-76-6,With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.933-76-6,4,5-Dichloro-2-methylpyridazin-3(2H)-one,as a common compound, the synthetic route is as follows.
Step C: Preparation of 4,5-dichloro-6-iodo-2-methyl-3(2H)-pyridazinone (0418) To 4,5-dichloro-2-methyl-3(2H)-pyridazinone (i.e. the product obtained in Example 1, Step B) (5.0 g, 27.9 mmol) dissolved in 80 mL tetrahydrofuran was added 2,2,6,6-bis(tetramethylpiperidine)zinc, magnesium chloride, lithium chloride complex 0.35M in toluene/tetrahydrofuran (i.e. Zn(TMP)2-LiCl-MgCl2 54 mL, 0.35 M in tetrahydrofuran/toluene) 18.75 mmol) over 3 to 5 min. The cloudy reaction mixture was stirred for 15 min and then iodine (8.5 g, 33.51 mmol) was added. The resulting mixture was stirred at ambient temperature for 15 min. The reaction mixture was quenched with aqueous sodium bisulfite solution (to remove excess iodine color), then water (200 mL) followed by 1 N aqueous hydrochloric acid (100 mL). The mixture was extracted with ethyl acetate (300 mL, then 200 mL). The resulting crude product which was purified by silica gel column chromatography eluting with 10% ethyl acetate in petroleum ether. A solid was triturated with diethyl ether and pentane, and the resulting pale yellow solid was dried (3 g). 1H NMR delta 3.83 (s, 3H).
933-76-6 4,5-Dichloro-2-methylpyridazin-3(2H)-one 120462, apyridazine compound, is more and more widely used in various fields.
Reference£º
Patent; E. I. DU PONT DE NEMOURS AND COMPANY; STEVENSON, Thomas Martin; SELBY, Thomas Paul; MARCUS, Kimberly Katherine; (118 pag.)WO2017/74992; (2017); A1;,
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