Acetyl chloride → 1-(2-phenyl-1H-indol-3-yl)ethanone

Participants

Reaction Steps

A mixture of 2-phenylindole (193.3 mg, 1.0 mmol) and acetyl chloride (92 μL, 1.3 mmol) in CH2Cl2 is treated with tin tetrachloride (97.4 μL, 1.9 mmol) at room temperature, shaken for 6 h, quenched with saturated NaHCO3 and extracted with ethyl acetate. The extracts are combined and concentrated in vacuo to afford the 3-acetyl-2-phenylindole intermediate. A suspension of the thus-obtained 3-acetyl-2-phenylindole (47 mg, 0.2 mmol) in isopropanol and concentrated HCl (5 μL) is treated with aminoguanidine bicarbonate, heated at 80° C. for 2 h, cooled to room temperature and concentrated in vacuo. The resultant residue is purified by HPLC to afford the title product, 21.0 mg (36% yield), identified by HPLC1 and mass spectral analyses, (M+H) 292, retention time 3.9 min.

Provenance & Evidence