With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.17973-86-3,3,6-Dibromopyridazine,as a common compound, the synthetic route is as follows.
Example 24 2-(2,4-Difluorophenyl)-1,1-difluoro-3-(1H-tetrazol-1-yl)-1-(6-(4-(trifluoromethyl)phenyl)pyridazin-3-yl)propan-2-ol (56) To a stirred solution of 3,6-dibromopyridazine (200 mg, 0.84 mmol) and 4-(trifluoromethyl)phenylboronic acid (159.7 mg, 0.84 mmol) in 1,2-dimethoxyethane (DME; 12 mL) was added 1M sodium carbonate (Na2CO3; 1.2 mL, 1.26 mmol) at RT, and the mixture was degassed by purging with argon for 30 min. To the resulting reaction mixture was added tetrakis(triphenylphosphine)palladium(0) (Pd(PPh3)4; 29.1 mg, 0.025 mmol), and the mixture was further degassed for 5 min at RT. The reaction mixture was stirred at reflux for 18 h. After complete consumption of the starting material (by TLC), the reaction mixture was cooled to RT, diluted with H2O (50 mL) and extracted with EtOAc (2*50 mL). The combined organic extracts were washed with H2O (40 mL) and brine (40 mL), dried over anhydrous Na2SO4 and concentrated under reduced pressure to obtain the crude material. Purification by silica gel column chromatography (eluting with 12% EtOAc/hexane) afforded a mixture of mono and bis-coupled products BC (150 mg, 2:1 ratio), which was taken to the next step without separation. (Note: Both compounds eluted at same Rf; all the characteristic protons were seen in the 1H NMR spectrum.) MS (ESI): 303 [M+H]+. To a stirred suspension of copper powder (0.75 g, 11.81 mmol) in DMSO (3 mL) was added ethyl 2-bromo-2,2-difluoroacetate (1.2 g, 5.92 mmol) at RT, and the mixture was stirred for 1 h. A solution of compound BC (0.9 g, mixture) in DMSO (7 mL) was added to the reaction mixture, and stirring was continued for another 18 h at RT. After completion of reaction (by TLC), the reaction mixture was quenched with satd NH4Cl solution (100 mL) and extracted with EtOAc (2¡Á200 mL). The combined organic extracts were washed with H2O (50 mL) and brine (50 mL), dried over anhydrous Na2SO4 and concentrated under reduced pressure to obtain the crude product. Purification by silica gel column chromatography (eluting with 15% EtOAc/hexane) afforded crude BD (0.7 g, as a mixture) which was taken for the next step without separation. (Note: All the characteristic protons were seen in the 1H NMR spectrum.) LC-MS: 347.8 [M+H]+ at 4.99 RT (73.75% purity).
17973-86-3, As the paragraph descriping shows that 17973-86-3 is playing an increasingly important role.
Reference£º
Patent; VIAMET PHARMACEUTICALS, INC.; US2012/329802; (2012); A1;,
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