5-Bromoindole → 5-[4-(3,6-Dihydro-4-phenyl-1(2H)-pyridinyl)-1-butynyl]-1H-indole

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Reaction Steps

A solution of 5-bromoindole (0.5 g, 0.0025 mol) and the acetylene prepared in Example 9, Step (a) in 15 mL of N-butylamine is degassed by bubbling in dry nitrogen for 15 minutes, and 0.06 g, (5.0×10-5 mol) of tetrakis (triphenylphosphine)palladium(O) is added. The flask is flushed with nitrogen and the mixture is headed at reflux for 18 hours. The solvent is removed under reduced pressure, and the residue is partitioned between 50 mL of dichloromethane and 50 mL of saturated aqueous sodium bicarbonate. The aqueous layer is extracted with 25 mL of dichloromethane and the combined organic layers are washed with 25 mL of water and dried (sodium sulfate), and the solvent is removed in vacuo. The residue is chromatographed (silica gel, 1% methanol/99% dichloromethane) to give the title compound containing 0.3 mol of water; mp 173°-174° C.

Provenance & Evidence