2-ETHOXY-3-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-PYRIDINE synthesis
- Product Name:2-ETHOXY-3-(4,4,5,5-TETRAMETHYL-[1,3,2]DIOXABOROLAN-2-YL)-PYRIDINE
- CAS Number:848243-23-2
- Molecular formula:C13H20BNO3
- Molecular Weight:249.11
57883-25-7
73183-34-3
848243-23-2
A suspension was prepared in DMSO (100 mL) with 3-bromo-2-ethoxypyridine (28.69 g, 142.0 mmol), bis(pinacolato)diboron (43.3 g, 170.5 mmol) and potassium acetate (41.8 g, 425.9 mmol). The suspension was degassed with nitrogen and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (5.8 g, 7.93 mmol) was added. The reaction mixture was stirred at 95 °C for 6 hours. After completion of the reaction, the reaction mixture was filtered through an Arbocel pad and washed with ethyl acetate (500 mL). The filtrate was concentrated under vacuum and the crude product was purified by silica gel column chromatography using a 50% cyclohexane solution of ethyl acetate as eluent to afford 2-ethoxypyridine-3-boronic acid pinacol ester as a red oil (34.4 g, 74% yield).1H NMR (400 MHz, CDCl3) data were as follows: δ 1.35 (s, 12H), 1.39 (m, 3H). 4.37 (m, 2H), 6.81 (m, 1H), 7.89 (m, 1H), 8.19 (m, 1H).Results of LCMS analysis: retention time (Rt) = 3.27 min, mass spectrum (MS) m/z 250 [MH]+.
57883-25-7
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73183-34-3
589 suppliers
$6.00/5g
848243-23-2
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$45.00/100mg
Yield:848243-23-2 74%
Reaction Conditions:
with (1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride;potassium acetate in dimethyl sulfoxide at 95; for 6 h;Inert atmosphere;
Steps:
B.10 Preparation 10 2-ethoxy-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine
A suspension of 3-bromo-2-ethoxypyridine (Preparation 1 1 , 28.69 g, 142.0 mmol), bis(pinacolato)diboron (43.3 g, 170.5 mmol), and potassium acetate (41 .8 g, 425.9 mmol) in DMSO (100 mL) was degassed with nitrogen and [1 ,1 '- bis(diphenylphosphinoferrocene]dichloro palladium (II) (5.8 g, 7.93 mmol) was added and the reaction mixture was stirred for 6 hours at 95 °C. The reaction mixture was filtered through a pad of Arbocel which was washed with ethyl acetate (500 mL). The filtrate was concentrated in vacuo and the crude material was purified by silica gel column chromatography eluting with 50% ethyl acetate in cyclohexane to afford the title compound as a red oil (34.4g, 74%). 1H NMR (400MHz, CDCl3): δ ppm 1 .35 (s, 12H), 1 .39 (m, 3H), 4.37 (m, 2H), 6.81 (m, 1 H), 7.89 (m, 1 H), 8.19 (m, 1 H). LCMS Rt = 3.27 minutes MS m/z 250 [MH]+
References:
WO2013/93688,2013,A1 Location in patent:Page/Page column 44-45
36178-05-9
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848243-23-2
66 suppliers
$45.00/100mg