Reaction of 1-vinylpyrrole-2-carbaldehydes with phosphorus pentachloride: a stereoselective synthesis of E-2-(2-dkhloromethylpyrrol-1-yl)vinylphospho-nyl dichlorides

摘要

1-Vinylpyrrole-2-carbaldehydes react with phosphorus pentachloride (benzene, 10-15 °C) to afford E-2-(2-dichloromethylpyrrol-1-yl)vinylphosphonium hexachlorophosphates in up to 85% yield, which after treatment with SO2 (benzene, rt) are converted into E-2-(2-dichloromethylpyrrol-1-yl)vinylphosphonyl dichlorides in 50-75% yields.