Pyridine → HCID 22905651, compound

Participants

Reaction Steps

To an ice-cold solution of N-isobutyryl-5-hydroxy-3,4,6-trimethylindoline (11b, 49 mg, 0.2 mmol) dissolved in methylene chloride (2 mL) were added sequentially pyridine (0.16 mL, 2 mmol) and acetic anhydride (0.1 mL, 1 mmol). The mixture was stirred over the range of 0° C. to room temperature for 17 h. The mixture was diluted with methylene chloride, transferred to a separatory funnel and washed sequentially with 10% hydrochloric acid, saturated aq. sodium bicarbonate and brine. Removal of solvents after drying (MgSO4) gave a viscous liquid, which was purified by flash column chromatography, using 1:4 ethyl acetate:hexanes as eluent, to afford the N-isobutyryl-5-acetoxy-3,4,6-trimethylindoline (12b, 45 mg, 77% yield) as a colorless solid, mp 118°-120° C. Spectral data: 1H NMR: δ 2.0 (s, 3H), 2.06 (s, 3H), 2.26 (s, 3H), 2.7 (quintet, 1H, J=6.7 Hz), 3.3 (t, 1H, J=6.7 Hz), 3.7 (dd, 1H, J=10.2, 1.2 Hz), 4.1 (t, 1H, J=9.3 Hz), 8.0 (s, 1H); CI-HRMS: calcd. for C17H24NO3 (M+H+) 290.1756, fnd. 290.1756.

Provenance & Evidence