Electric Literature of 1352625-30-9, 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. 1352625-30-9, name is 3-Bromo-6-fluoropyrazolo[1,5-a]pyridine, molecular formula is C7H4BrFN2, 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.
c) 6-Fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyridine A mixture of 3-bromo-6-fluoropyrazolo[1,5-a]pyridine (Preparation 103b, 0.300 g, 1.4 mmol), potassium acetate (0.492 g, 5.0 mmol) and bis(pinacolato)diboron (2.77 g, 10.9 mmol) in 1,4-dioxane (5 mL) contained in a Schlenck vessel was submitted to three vacuum-argon cycles and tetrakis(triphenylphosphine)palladium(0) (0.380 g, 0.33 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 purified by reverse phase chromatography (C-18 silica from Waters, water/acetonitrile/methanol as eluents [0.1% v/v formic acid buffered] 0% to 100%) to give the title compound (0.130 g, 36%) as a yellow solid. LRMS (m/z): 263 (M+1)+.1H NMR (300 MHz, CDCl3) delta ppm (two sets of peaks are seen in the NMR due to the presence of both the boronate and boronic acid): NMR of boronate: 1.21 (s, 12H), 7.56 (m, 1H), 8.02 (m, 1H), 8.36 (s, 1H), 9.16 (m, 1H).; PREPARATION 104 2-(6-Fluoropyrazolo[1,5-a]pyridin-3-yl)-9-(tetrahydro-2H-pyran-4-yl)-7-((2-(trimethylsilyl)ethoxy)methyl)-7H-purin-8(9H)-one A mixture of 2-chloro-9-(tetrahydro-2H-pyran-4-yl)-7-{[2-(trimethylsilyl)ethoxy]methyl}-7,9-dihydro-8H-purin-8-one (Preparation 3, 0.150 g, 0.39 mmol), 6-fluoro-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyrazolo[1,5-a]pyridine (Preparation 103, 0.183 g, 0.70 mmol) and potassium acetate (0.134 g, 1.37 mmol) in 1,4-dioxane (5 mL) and water (1.5 mL) contained in a Schlenck vessel was submitted to three vacuum-argon cycles and tetrakis(triphenylphosphine)palladium(0) (0.040 g, 0.03 mmol) was then added. The mixture was further submitted to three vacuum-argon cycles, sealed and then was stirred and heated under microwave irradiation (“Initiator sixty” from Biotage) at 120 C under an atmosphere of argon. After 40 minutes, further 2-chloro-9-(tetrahydro-2H-pyran-4-yl)-7-{[2-(trimethylsilyl)ethoxy]methyl}-7,9-dihydro-8H-purin-8-one (0.060 g, 0.16 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.020 g, 0.017 mmol) were added and heating was continued for 90 minutes. The reaction mixture was evaporated and then was partitioned between ethyl acetate and water and the organic layer was dried (MgSO4) and concentrated. The residue was purified by flash chromatography (3:1 to 2:1 hexanes/ethyl acetate) to give the title compound (0.096 g, 50%) as pale yellow solid. LRMS (m/z): 485 (M+1)+.1H NMR (300 MHz, CDCl3) delta ppm 0.06 (s, 9H), 1.00 (t, 2H), 1.80 (m, 2H), 2.91 (dq, 2H), 3.49 (s, 2H), 3.68 (m, 2H), 4.22 (m, 2H), 4.63 (m, 1H), 5.25 (s, 2H), 7.38 (t, 1H), 8.40 (s, 1H), 8.52 (m, 1H), 8.65 (dd, 1H), 8.78 (s, 1H).
According to the analysis of related databases, 1352625-30-9, the application of this compound in the production field has become more and more popular.
Reference:
Patent; ALMIRALL, S.A.; EASTWOOD, Paul Robert; GONZALEZ RODRIGUEZ, Jacob; GOMEZ CASTILLO, Elena; BACH TANA, Jordi; WO2011/157397; (2011); A1;,
Pyridine – Wikipedia,
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