HCID 59132625, compound → HCID 42603138, compound

Participants

Reaction Conditions

Reaction Steps

To a stirring THF (120 mL) solution of compound 12.2 (13.8 g, 37.5 mmol) under nitrogen was added 1-propynylmagnesium bromide in THF (0.5 N, 97.5 mL) over a period of 20 minutes. After the addition was complete, the reaction mixture was stirred for 20 minutes, quenched with saturated aqueous NH4Cl (50 mL) and extracted with ethyl acetate (3×50 mL). The combined extracts were washed with water, dried over MgSO4, filtered, and concentrated to a brown oil. A solution of this brown oil in 5:1 pyridine-water (360 mL) was heated at 100° C. for 36 h. The reaction mixture was cooled to room temperature and put in an ice-water bath. Concentrated HCl was carefully added to pH ˜2. The resulting suspension was extracted with ethyl acetate (200 mL×3), dried over MgSO4, filtered, and concentrated to an off-white solid. Recrystalization from ethanol gave 9.5 g (78%) of compound 12 as a white powder. 1H NMR (500 MHz) DMSO-d6) δ 12.2 (s, 1H); 7.37 (d, 2H, J=8.5 Hz); 7.27 (d, 2H, J=8.5 Hz); 6.95 (d, 2H, J=8.0 Hz); 6.94 (d, 2H, J=8.5 Hz); 4.99 (s, 2H); 3.95 (m, 1H); 3.76 (s, 3H); 2.60 (m, 2H); 1.78 (d, 3H, J=1.5 Hz). MS ESI (neg.) m/e: 323.0 (M−1).

Provenance & Evidence