Indole → 1-(1-(1H-indol-3-yl)-3,4-dihydroisoquinolin-2(1H)-yl)ethanone

Participants

Reaction Steps

To a solution of 3,4-dihydroisoquinoline (4.00 g, 30.5 mmol) and CH3CN (50 mL) at 0° C. was added acetyl chloride (2.13 mL, 30.5 mmol) over 2 min. The reaction was stirred 30 min and 1H-indole (3.57 g, 30.5 mmol) and triethylamine (4.25 mL, 30.5 mmol) in CH3CN (5 mL) were added and the reaction warmed to RT. The reaction was stirred under N2 3 h, then quenched with 10% HCl (100 mL), and extracted with CH2Cl2 (3×100 mL). The combined organic layers were washed with NaHCO3 (100 mL), dried (Na2SO4), and concentrated to give the crude product as a white solid (9.2 g). The solid was dissolved in CH2Cl2 (50 mL) to give a suspension which was filtered and the solid collected. The white solid (3.55 g) was recrystallized from hot acetone (230 mL) and cooled at −20° C. overnight to give 1-(1-(1H-indol-3-yl)-3,4-dihydroisoquinolin-2(1H)-yl)ethanone as a white crystalline solid.

Provenance & Evidence