Pivaloyl chloride → HCID 44199847, compound

Participants

Reaction Conditions

Reaction Steps

Diethylaluminum chloride (1.0 M in hexanes, 19.1 mL, 19.1 mmol) was added to a suspension of impure 2-ethynyl-5H-pyrrolo[2,3-b]pyrazine (0.911 g, 6.36 mmol) in 25 mL of dichloromethane at 0-5° C. The mixture was stirred at 0-5° C. for 30 min., then pivaloyl chloride (7.8 mL, 63.6 mmol) was slowly added. The mixture was heated to reflux and stirred for 6 h then cooled to 0-5° C. Sat. Aq. NaHCO3 (50 mL) was carefully added, and the resulting mixture was diluted with 100 mL of ethyl acetate and filtered through a plug of Celite, rinsing with ethyl acetate and water. The filtrate layers were separated, and the aqueous layer extracted with 250 mL of ethyl acetate. The combined organic layers were dried over MgSO4, filtered and concentrated to a residue. Silica gel chromatography (20->60% EtOAc/hexanes) afforded 0.180 g (12%) of 1-(2-ethynyl-5H-pyrrolo[2,3-b]pyrazin-7-yl)-2,2-dimethyl-propan-1-one as a brown solid.

Provenance & Evidence