Water → HCID 18786079, compound

Participants

Reaction Steps

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##

Provenance & Evidence