Synthetic Route of 188577-68-6, With the rapid development and complex challenges of chemical substances, the synthesis of new drugs is usually one of the most effective ways to increase yield.188577-68-6, name is 4,5-Dichloropyridin-2-amine, molecular formula is C5H4Cl2N2, molecular weight is 163.01, as common compound, the synthetic route is as follows.
INTERMEDIATE 2 4,5-Dichloro- V-nitropyridine-2-amine 4,5-Dichloropyridin-2-amine (INTERMEDIATE 1, 45.2 g, 283.0 mmol) was added to 270 mL of ice cold cone. H2SO4, in small portions over ca 20 min. When dissolved, cone. HNO3 (22 g) was added dropwise and the mixture was stirred at ca 5 C for 3.5 h. LCMS indicated total conversion to expected product. The cold mixture was poured on crushed ice/water mixture (3 L), stirred for ca 5 min and then filtered. The solid was collected and slurried in ice cold water (500 mL) and filtered. The procedure was repeated until neutral pH. When semi dry on the filter, the solid was dissolved in EtOAc (ca. 3 L) , washed with brine (ca. 100 mL) and the organic layer was dried with Na2S04, filtered, and evaporated to furnish 46.2 g (78%) of 97% pure title product as beige-orange solid. 1H NMR (600 MHz, CD3OD) delta ppm 8.47 (s, 1 H) 8.08 (s, 1 H). MS: (ESI+) m/z 208, 210, 212 [M+H]+, di-chlorine isotopic pattern. INTERMEDIATE 3 4,5-Dichloro-3-nitropyridine-2-amine 4,5-Dichloro-N-nitropyridin-2-amine (INTERMEDIATE 2, 20.0 g, 96.2 mmol) was added to 200 mL of cone. H2S04 at room temperature. After stirring at 40 C for 2.5 h the mixture was cooled to below room temperature and poured onto crushed ice (2 L) while stirring. After the ice had melted, the volume was adjusted to ca. 2 L with ice cold water and the yellow precipitate was collected by filtration and washed with ice cold water until neutral pH (3 x 250 mL). The solid was allowed to semi-dry on the filter and was then dissolved in EtOAc (ca. 800 mL). The organic phase was washed with 0.25 M NaOH (3×30 mL), water (3×15 mL) and brine (15 mL), dried (Na2S04), filtered and the solvent evaporated to furnish 11.7 g (59%) of 99% pure title product as yellow solid. 1H NMR (600 MHz, CD3OD) delta ppm 8.26 (s, 1 H). MS: (ESI+) m/z 208, 210, 212 [M+H]+ chlorine isotopic pattern.
Statistics shows that 188577-68-6 is playing an increasingly important role. we look forward to future research findings about 4,5-Dichloropyridin-2-amine.
Reference:
Patent; KANCERA AB; MELLSTEDT, Hakan; BYSTROeM, Styrbjoern; VAGBERG, Jan; OLSSON, Elisabeth; (274 pag.)WO2016/124553; (2016); A1;,
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