2,6-Di-tert-butyl-4-methylphenol → 2-phenyl-6,7,8,9-tetrahydro-5H-pyrido[3,2-b]indole

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Reaction Steps

A mixture of 2-trifluoromethanesulfonyloxy-6,7,8,9-tetrahydro-5H-pyrido[3,2-b]indole (99 mg, 0.31 mmol), phenyltrimethyltin (300 mg, 1.24 mmol), lithium chloride (40 mg, 0.93 mmol), tetrakis(triphenylphosphine)palladium(0) (7 mg, 0.02 mol. eq.) and a crystal of 2,6-di-tert-butyl-4-methylphenol in 1,4-dioxane (2 mL) were refluxed for 10 hours under an atmosphere of nitrogen. The mixture was cooled and poured into ether and filtered through celite. The ether was extracted with 15% hydrochloric acid. The pH of the acidic, aqueous phase was raised to about pH 10 with 28% ammonium hydroxide, then was extracted with ether. The extract was washed with water and brine, dried over sodium sulfate, filtered and concentrated. Purification by silica-gel chromatography (30% ethyl acetate in hexanes) gave 2-phenyl-6,7,8,9-tetrahydro-5H-pyrido[3,2-b]indole (Compound 4) as a white solid, m.p. 164°-165° C.

Provenance & Evidence