反应详情

To a mixture of 5-bromo-4′-methoxy-3H-spiro[benzofuran-2,1′-cyclohexan]-3-one (Intermediate 12, 2.8 g, 9.00 mmol) and 2-methylpropane-2-sulfinamide (2.024 g, 16.20 mmol) in methyl THF (15 mL) was added titanium ethoxide (3.71 mL, 18.00 mmol) and the reaction was heated to reflux. After 21 h the reaction was allowed to cool to r.t. whereafter it was diluted with EtOAc (150 mL). Water (12 mL) was added dropwise over 10 min under vigorous stirring and then the mixture was left standing without stirring for 1.5 h. The solids were filtered off and the organics were evaporated. The crude product was purified by flash chromatography using a gradient of 0%-50% EtOAc in heptane, yielding 2.41 g of the title compound (65% yield): 1H NMR (500 MHz, CDCl3) δ ppm 1.33 (s, 9 H), 1.81 (m, 6 H), 2.12 (d, 2 H), 3.33 (m, 1 H), 3.42 (s, 3 H), 6.94 (d, 1 H), 7.59 (dd, 1 H), 8.53 (m, 1 H); MS (ES+) m/z 415 [M+H]+.

1. temperaturethe reaction was heated to reflux
2. waitthe mixture was left
3. stirringwithout stirring for 1.5 h
4. filtrationThe solids were filtered off
5. customthe organics were evaporated
6. customThe crude product was purified by flash chromatography