Reference of 875781-18-3, Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps,and cheap raw materials. 875781-18-3, name is 5-Bromo-3-iodo-1H-pyrazolo[3,4-b]pyridine. A new synthetic method of this compound is introduced below.
5-bromo-3-iodo-1H-pyrazolo[3,4-b]pyridine ((II), 10.44 g, 32.2 mmol) was combined with DMF, MeOH and triethylamine (75 mL each). The vessel was evacuated and flushed with argon (4x). XantPhos (1.12 g, 1.93 mmol) and Pd(OAc)2 (217 mg, 0.97 mmol) were added and carbon monoxide (generated from formic acid and sulfuric acid) was bubbled through the solution while heating to 60 C. The mixture was stirred under an atmosphere of carbon monoxide (balloon) for 8 h. Every 1.5 h carbon monoxide was bubbled through the solution for 5 minutes. The mixture was concentrated under reduced pressure and the residue was triturated with 2N HCl. The solids were heated at 95 C in about 100 mL 1N NaOH overnight. After cooling to RT, the mixture was acidified with conc. HCl and the precipitate collected by suction filtration and washed with water. The solids were dried in an oven at 110 C to constant mass. The solids were sonicated in 100 mL of toluene for 5 minutes and stirred for 30 minutes. The product was filtered, washed with an additional 20 mL of toluene and dried at 110 C. Yield: 7.92 g HPLC purity: > 99 %, 1H NMR (200 MHz, DMSO) delta 8.64 (d, J = 7.9 Hz, 2H), 5.69 (bs, 1H); 13C NMR (50 MHz, DMSO) delta 163.27, 150.97, 149.67, 136.69, 132.65, 115.73, 113.6; [M-H]- = 239.9 / 241.9.
At the same time, in my other blogs, there are other synthetic methods of this type of compound,875781-18-3, 5-Bromo-3-iodo-1H-pyrazolo[3,4-b]pyridine, and friends who are interested can also refer to it.
Reference:
Patent; HEPAREGENIX GMBH; PRAEFKE, Bent; KLOeVEKORN, Philip; SELIG, Roland; ALBRECHT, Wolfgang; LAUFER, Stefan; (157 pag.)WO2019/149738; (2019); A1;,
Pyridine – Wikipedia,
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