Pyridine → N-[4-(3-cyano-1-ethyl-6-methoxy-1H-indol-2-ylethynyl)-phenyl]-dimethylphosphinic amide

Participants

Reaction Steps

2-(3-Aminophenylethynyl)-1-ethyl-6-methoxy-1H-indole-3-carbonitrile (100 mg, 0.32 mmol), prepared as described in Example 1H, is dissolved in pyridine (300 μL) at 0° C. Dimethylphosphinic chloride (60 mg, 0.53 mmol) in THF (300 μL) is added. The reaction is stirred at room temperature for 2 hours. The reaction mixture is diluted in EtOAc, and is washed with aqueous HCl followed by brine. The organic layer is dried and concentrated. Purification by silica chromatography (acetone) yields N-[4-(3-cyano-1-ethyl-6-methoxy-1H-indol-2-ylethynyl)-phenyl]-dimethylphosphinic amide (65 mg, 52%), compound 227, as a pure white solid. The silica column is then flushed with 9/1 CH2Cl2/MeOH to yield 9 mg of N-[4-(3-cyano-1-ethyl-6-methoxy-1H-indol-2-ylethynyl)-phenyl]-bis-(dimethylphosphinic) amide as a by-product.

Provenance & Evidence