With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.18480-53-0,3,4-Dichloroisothiazole-5-carboxylic acid,as a common compound, the synthetic route is as follows.
3,4-Dichloroisothiazol-5-ylcarboxylic acid (400 mg, 2.02 mmol) was dissolved in abs. dichloromethane (20 ml), and triethylamine (0.85 ml, 6.06 mmol) was added. After stirring at room temperature for 5 minutes, pyrrolidine-i-amine (209 mg, 2.42 mmol) and 2,4,6-tripropyl-1,3, 5,2,4,6-trioxatriphosphorinane 2,4,6-trioxide (1.80 ml, 3.03 mmol, 50percent solution in tetrahydrofuran) were added. The resulting reaction mixture was stirred at room temperature for a further 30 minutes, and then water, sat. sodium hydrogencarbonate solution and dichloromethane were added. The aqueous phase was repeatedly extracted vigorously with dichloromethane, and the combined organic phases were then dried over magnesium sulfate, filtered and concentrated. Final purification of the resulting crude product by colunm chromatography gave 3,4-dichloro-N-(pyr- rolidin-i-yl)-i,2-thiazole-5-carboxamide in the form of a colorless solid (520 mg, 92percent of theory). ?H-NMR (400 MHz, CDC13 oe, ppm) 3.38-3.28 (m, 2H), 2.73-2.64 (m, 2H), 2.03-1.98 (m, 4H). 3,4-Dichloro-N-(pyrrolidin- 1 -yl)-i ,2- thiazole-5-carboxamide (120 mg, 0.45 mmol) was dissolved in abs. tetrahydroffiran (5 ml) under argon, and sodium hydride (40 mg, 1.99 mmol, 60percent purity) was added at room temperature. Stirring at room temperature for 30 minutes was followed by the addition of picolyl chloride (HC1 salt, 74 mg, 0.45 mmol), and the resulting reaction mixture was stirred under reflux conditions for approx. 3 hours. After cooling to room temperature, sat. sodium hydrogencarbonate solution, water and dichloromethane were added. The aqueous phase was repeatedly extracted vigorously with dichloromethane, and the combined organic phases were then dried over magnesium sulfate, filtered and concentrated. Final purification of the resulting crude product by colunm chromatography gave 3,4-dichloro-N-(pyridin-2-yl- methyl)-N-(pyrrolidin- 1 -yl)-i ,2-thiazole-5-carboxamide in the form of a colorless solid (112 mg, 69percent of theory). ?H-NMR (400 MHz, CDC13 oe, ppm) 8.62 (m, 1H), 7.71-7.67 (m, 1H), 7.53 (m, 1H), 7.33 (m, 1H), 5.15 (s, 2H), 4.18-4.13 (m, 2H), 3.71-3.66 (m, 2H), 2.30-2.24 (m, 2H), 2.13-2.08 (m, 2H).
18480-53-0, As the paragraph descriping shows that 18480-53-0 is playing an increasingly important role.
Reference£º
Patent; Bayer CropScience Aktiengesellschaft; FRACKENPOHL, Jens; BOJACK, Guido; BRUENJES, Marco; HELMKE, Hendrik; LEHR, Stefan; BRUECHNER, Peter; TIEBES, Joerg; MOSRIN, Marc; DITTGEN, Jan; SCHMUTZLER, Dirk; DESBORDES, Philippe; (92 pag.)US2018/206498; (2018); A1;,
Isothiazole – Wikipedia
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