3-(8-Chloroimidazo[1,5-A]pyrazin-3-YL)cyclobutanone → 3-(8-Chloroimidazo[1,5-a]pyrazin-3-yl)-1-methylcyclobutanol

Participants

Reaction Conditions

Reaction Steps

3-(8-Chloroimidazo[1,5-a]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 warm 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, 3H), 2.74-2.60 (m, 4H), 3.75-3.39 (m, 1H), 7.35 (d, J=5.04 Hz, 1H), 7.71 (d, J=5.00 Hz, 1H) and 7.86 (s, 1H). MS (ES+): m/z 238.15 and 240.17 [MH+].

Provenance & Evidence