Boron trifluoride etherate → ethyl 5-chloro-3-(phenylthio)-1H-indole-2-carboxylate

Participants

Reaction Steps

To a partial suspension of ethyl 5-chloroindole-2-carboxylate (698 mg, 3.1 mmol) and N-(phenylthio)succinimide (683 mg, 3.3 mmol) in anhydrous methylene chloride (20 mL) at ambient temperature under an inert gas atmosphere was added boron trifluoride etherate (0.12 mL, 1.0 mmol). The reaction was monitored by tlc (thin layer chromatography) until complete. After 2 hours, the reaction was diluted with chloroform and neutralized with aq. NaHCO3. The organic layer was dried (Na2SO4), filtered through a pad of charcoal, and the solvents evaporated. The residue was triturated with hexanes as the product crystallized out to yield the title product, mp 160°-162° C. [see Table II, mp 163°-164° C⟧ This material was used as is.

Provenance & Evidence