Hydrochloric Acid → 1-(benzenesulfonyl)-1H-indole-5-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

15.8 g Indole-5-carboxaldehyde were dissolved in 300 ml tetrahydrofuran and cooled to 0° C. Then, 5.12 g sodium hydride (55% in mineral oil) were added in small portions followed by slow, trop by trop addition of 15.2 ml of benzenesulfonyl chloride. The reaction mixture was then warmed up to ambient temperature and stirring continued for 16 hours. It was then poured onto ice, neutralized to pH 4 with HCl (1N) and extracted 3 times with ethyl acetate. The combined organic phases were washed with water, dried over magnesium sulfate and evaporated to give a crude product which was purified by chromatography (silicagel, eluent: gradient of n-heptane/ethyl acetate) to yield 4.09 g 1-benzenesulfonyl-1H-indole-5-carbaldehyde as rose solid.

Provenance & Evidence