反应详情

温度

-78 °C

3-(8-Chloroimidazo[1,5-α]pyrazin-3-yl)cyclobutanone (1.95 g, 8.80 mmol) in anhydrous THF (77.78 mL) at −78° C. under an atmosphere of nitrogen was treated slowly with a 3.0 M solution of methylmagnesium chloride in THF (5.9 mL). The solution stirred for 3 hr at −78° C. then quenched with 40 mL of semi-saturated aqueous NH4Cl (NH4Cl dilution in 1:1 mixture with water) at −78° C. and allowed to warn up to rt. The mixture was then extracted with EtOAc (3×40 mL) and the combined extracts washed with brine (30 mL), dried over magnesium sulfate, filtered and concentrated in vacuo. The crude solid was purified by chromatography over silica gel eluting with 1:1 EtOAc/DCM to 4% MeOH in (1:1) EtOAc/DCM to afford desired product. 1H-NMR (400 MHz, CDCl3) δ ppm 1.54 (s, 3 H), 2.74-2.60 (m, 4 H), 3.75-3.39 (m, 1 H), 7.35 (d, J=5.04 Hz, 1 H), 7.71 (d, J=5.00 Hz, 1 H) and 7.86 (s, 1 H). MS (ES+): m/z 238.15 and 240.17 [MH+].

1. customthen quenched with 40 mL of semi-saturated aqueous NH4Cl (NH4Cl dilution in 1:1 mixture with water) at −78° C.
2. customto warn up to rt
3. extractionThe mixture was then extracted with EtOAc (3×40 mL)
4. washthe combined extracts washed with brine (30 mL)
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe crude solid was purified by chromatography over silica gel eluting with 1:1 EtOAc/DCM to 4% MeOH in (1:1) EtOAc/DCM