As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 55405-67-9, name is 3-Bromopyrazolo[1,5-a]pyrimidine, molecular formula is C6H4BrN3, The compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below. Product Details of 55405-67-9
PREPARATION 107 3-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyrimidine [Show Image] A mixture of 3-bromopyrazolo[1,5-a]pyrimidine (1.00 g, 5.1 mmol), potassium acetate (1.78 g, 18.1 mmol) and bis(pinacolato)diboron (5.77 g, 22.7 mmol) in 1,4-dioxane (20 mL) contained in a Schlenck vessel was submitted to three vacuum-argon cycles and bis(triphenylphosphine)palladium(II) dichloride (0.180 g, 0.26 mmol) was then added. The mixture was further submitted to three vacuum-argon cycles, sealed and then was stirred and heated to 100 C. After 20 hours, the reaction mixture was cooled, evaporated and then taken up in pentane and filtered through diatomaceous earth (Celite) and the filter cake was washed with a mixture of ethyl acetate/ether (3:2). The combined filtrate and washings were evaporated and the residue was stirred with n-pentane (15 mL) at -40 C for 30 minutes. The solid was filtered, washed with cold pentane and dried in vacuo to give the title compound (1.66 g, >100%) as a solid which was used without further purification. LRMS (m/z): 246 (M+1)+.1H NMR (300 MHz, CDCl3) delta ppm 1.26 (s, 12H), 6.89 (dd, 1H), 8.44 (s, 1H), 8.63 – 8.83 (m, 2H).
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Reference:
Patent; Almirall, S.A.; EP2397482; (2011); A1;,
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia