Diethyl Ether → HCID 58125491, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-3-carboxylic acid methoxy-methyl-amide (9.02 g, 42.7 mmol) in tetrahydrofuran (300 mL) was cooled to 0° C. 3 M methylmagnesium bromide in ether (15.3 mL, 43 mmol) was added and the reaction was stirred at 0° C. for 30 minutes, then warmed to room temperature. Additional 3 M methylmagnesium bromide in ether (15.3 mL, 43 mmol) was added after 1 hour, and the mixture was stirred at room temperature overnight, then the volatiles were removed in vacuo. The residue was partitioned between EtOAc (100 mL) and saturated NaHCO3 solution (150 mL). The aqueous layer was extracted with EtOAc (2×100 mL), and the combined organic layers were washed with brine (3×50 mL), dried (Na2SO4), filtered and concentrated. Flash chromatography (0 to 4% MeOH in DCM) afforded the ketone (5.79 g, 82%) as a solid. 1H NMR (400 MHz, DMSO-d6) δ7.69 (s, 1H), 4.44 (t, 2H, J=5.25 Hz), 4.09 (t, 2H, J=6.10 Hz), 2.23 (s, 3H), 2.22-2.17 (m, 2H).

Provenance & Evidence