反应详情

A 71.5 g (0.14 mol) sample of [[4-fluoro-2[(1-oxo-2-propenyl)amino]phenyl]-methyl]triphenylphosphonium bromide was suspended in 1.6 L of toluene and heated under reflux briefly with azeotropic removal of water. A 180 mL (0.18 mol) solution of 1M potassium t-butoxide in THF was added dropwise under Ar. The mixture was heated under reflux for one hour, cooled, washed with dilute HCl and filtered. The organic phase was washed with brine, dried (MgSO4) and concentrated. The residue was crystallized from methyl t-butyl ether (MTBE)/hexane. The precipitated triphenylphosphine oxide was collected and washed with MTBE. The combined filtrates were concentrated and flash chromatographed twice using EtOAc:hexane 1:10 as eluant. There was obtained 11.3 g (50%) of 2-ethenyl-6-fluoro-1H-indole: Cl-MS m/z=162 (M+H). 1H NMR (CDCl3) δ 8.1 (br s, 1H); 7.5 (m, 1H); 7.0 (d, 1H); 6.85 (m, 1H); 6.7 (m, 1H); 6.5 (s, 1H); 5.5 (d, 1H); 5.25 (d, 1H). ##STR19##

1. temperatureheated
2. temperatureThe mixture was heated
3. temperatureunder reflux for one hour
4. temperaturecooled
5. washwashed with dilute HCl
6. filtrationfiltered
7. washThe organic phase was washed with brine
8. dry with materialdried (MgSO4)
9. concentrationconcentrated
10. customThe residue was crystallized from methyl t-butyl ether (MTBE)/hexane
11. customThe precipitated triphenylphosphine oxide was collected
12. washwashed with MTBE
13. concentrationThe combined filtrates were concentrated
14. customflash chromatographed twice using EtOAc:hexane 1:10 as eluant