A new synthetic route of

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.55405-67-9, name is 3-Bromopyrazolo[1,5-a]pyrimidine, molecular formula is C6H4BrN3, molecular weight is 198.0201, as common compound, the synthetic route is as follows.COA of Formula: C6H4BrN3

To a stirred solution of compound 13f (27.8 mmol) in 1,4-dioxane (120 mL) was added B2Pm2 (126 mmol) and KOAc (101 mmol) at rt. The resulting mixture was purged with Ar for 45min, PdCl2(PPli3)2 (1.5 mmol) was added and the mixture again purged with Ar for 30min. The resulting mixture was heated to 1000C for 15h. The reaction mixture was concentrated to obtain a viscous mass, which was charged over afluorosil plug, washed with pentane, followed by 60% EtOAc/Pet ether. The relevant fractions were concentrated to obtain a crude compound 13g as a pale yellow solid. The crude compound 13g was stirred with pentane (25mL) at -400C for 30min, filtered, washed with cold pentane (5mL) and dried under vacuum to obtain sufficiently pure compound (3.5g, 51.4%). TLC system: Ethyl acetate: Petroleum ether (2:3) Rf value: 0.4. (M + H): 246.3.

At the same time, in my other blogs, there are other synthetic methods of this type of compound,55405-67-9, 3-Bromopyrazolo[1,5-a]pyrimidine, and friends who are interested can also refer to it.

Reference:
Patent; VERTEX PHARMACEUTICALS INCORPORATED; WO2009/85913; (2009); A1;,
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia