4-Nitrobenzaldehyde → 2-ethyl-3-(4-nitrobenzyl)-1H-indole

Participants

Reaction Steps

In an ice water bath, trifluoroacetic acid (4.4 g, 38.6 mmol), triethylsilane (9.02 g, 77.6 mmol), dichloromethane 15 mL were added into a reaction vessel. After stirring for 5 min, a dichloromethane solution dissolving 2-ethyl-1H-indole (3.74 g, 25.8 mmol) and p-nitro benzaldehyde (4.29 g, 28.4 mmol) was added dropwise slowly into the reaction vessel. After completion of dropwise addition it was reacted maintaining this temperature for 1 h, adjusted to pH=8-9 with 2 M solution of sodium hydroxide. An aqueous solution of sodium chloride was added, and extracted with dichloromethane. The extract was dried over anhydrous sodium sulfate, concentrated to dryness to obtain a red brown solid, washed with a small amount of diethyl ether to obtain a yellow powdered solid 3 g, at a yield of 41.5%.

Provenance & Evidence