反应详情

A mixture of Example 9D (11.6 g, 40 mmol) and dimethyl sulfate (20.2 g, 160 mmol) in toluene (10 mL) was heated at 80° C. for 24 hours. The mixture was cooled to room temperature, and concentrated under pressure. The residue was purified by flash chromatography (silica gel, eluted with a gradient of 10-50% hexane in solvent B, solvent B: 10:1:0.5 ethyl acetate:methanol:triethylamine) to afford 8.7 g (72%) of title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 0.41-0.53 (m, 4H), 1.15-1.27 (m, 1H), 1.38 (s, 9H), 3.98 (s, 3H), 4.20 (d, J=7.12 Hz, 2H), 6.70 (s, 1H); MS (ESI) m/z 304 [M+H]+, 302 [M−H].

1. concentrationconcentrated under pressure
2. customThe residue was purified by flash chromatography (silica gel
3. washeluted with a gradient of 10-50% hexane in solvent B, solvent B