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.916325-85-4, name is 5-Bromo-1H-pyrazolo[3,4-b]pyridine-3-carboxylic acid, molecular formula is C7H4BrN3O2, molecular weight is 242.03, as common compound, the synthetic route is as follows.name: 5-Bromo-1H-pyrazolo[3,4-b]pyridine-3-carboxylic acid
To a solution of 5-bromo-1H-pyrazolo[3,4-b]pyridine-3-carboxylic acid (XXXIV) (1.6 Kg, 6.6 mol) in anhydrous MeOH (32 L) was added H2SO4 (160 mL). The reaction was slowly heated to 70oC and stirred for 20 hours. The solution was concentrated under vacuum to a volume of 1.6 L. The residue was partitioned between DCM (120 L) and aqueous 10% NaHCO3 (32 L). The organic phase was separated and washed with aqueous 25% NaCl (32 L), dried over Na2SO4 and concentrated to a volume of 4.8 L. The product was crystallized by charging the solution with 3 x n-heptane (8 L) while concentrating the volume to 4.8 L after each addition of n- heptane. The solid was filtered and dried under vacuum at 50oC to produce methyl 5-bromo-1H- pyrazolo[3,4-b]pyridine-3-carboxylate (XXXV) (1.53 Kg, 6.0 mol, 80.6% purity, 90.4% assay yield).1H NMR (DMSO-d6, 400 MHz) d ppm 3.95 (s, 3H), 8.62 (d, J=2Hz, 1H), 8.73 (d, J=2.4Hz, 1H), 14.78 (brs, 1H); ESIMS found C8H6BrN3O2 m/z 256.0 (M+H).
At the same time, in my other blogs, there are other synthetic methods of this type of compound,916325-85-4, 5-Bromo-1H-pyrazolo[3,4-b]pyridine-3-carboxylic acid, and friends who are interested can also refer to it.
Reference:
Patent; SAMUMED, LLC; KC, Sunil Kumar; MITTAPALLI, Gopi Kumar; CHIRUTA, Chandramouli; HOFILENA, Brian Joseph; (128 pag.)WO2019/241540; (2019); A1;,
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