反应详情

Isopropylmagnesium chloride (2.0M in THF; 5.7 ml, 11.4 mmol) was added dropwise to a stirred, cold (−78° C.) solution of 3-bromo-8-fluoro-7-[2-(triethylsilyloxy)prop-2-yl]imidazo[1,2-α]pyridine (4.0 g, 10.3 mmol) in THF (80 ml). After 10 min, tri-n-butyltin chloride (3.22 ml, 11.9 mmol) was added in a single portion and the mixture was stirred for 30 min, then warmed to ambient temperature. 2,4-Dichloropyrimidine (2.31 g, 15.5 mmol) was added and the mixture degassed by bubbling through N2. Tetrakis(triphenylphosphine)palladium(0) (1.19 g, 1.03 mmol) and copper(I) iodide (19.7 mg, 0.1 mmol) were then added in single portions and the reaction was heated to reflux for 18 h. On cooling, water (80 ml) was added and the phases separated. The aqueous was extracted with EtOAc (40 ml) and the combined organics washed with brine (40 ml), dried over MgSO4, filtered and concentrated in vacuo. Purified by column chromatography (silica, 0 to 5% MeOH in CH2Cl2) and the semi-pure product washed with 1:2 Et2O/isohexane to afford 3-(2-chloropyrimidin-4-yl)-8-fluoro-7-[2-(triethylsilyloxy)prop-2-yl]imidazo[1,2-α]pyridine as a white amorphous solid (3.4 g): m/z (ES+) 421 (100%, [MH]+) and 423 (30).

1. customthe mixture degassed
2. customby bubbling through N2
3. temperaturethe reaction was heated
4. temperatureto reflux for 18 h
5. temperatureOn cooling
6. customthe phases separated
7. extractionThe aqueous was extracted with EtOAc (40 ml)
8. washthe combined organics washed with brine (40 ml)
9. dry with materialdried over MgSO4
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customPurified by column chromatography (silica, 0 to 5% MeOH in CH2Cl2)
13. washthe semi-pure product washed with 1:2 Et2O/isohexane