Sodium Hydroxide → 3-(4-Isopropylphenyl)-1',4,6,7-tetramethylspiro[benzofuran-2(3H),4'-piperidine]-5-amine

Participants

Reaction Steps

A solution of nitrosyl tetrafluoroborate (470.7 mg, 4.03 mmol) in acetonitrile (40 ml) was cooled to 0° C. To the solution was added a solution of 3-(4-isopropylphenyl)-1′,4,6,7-tetramethylspiro[benzofuran-2(3H),4′-piperidine] (479.1 mg, 1.32 mmol) in acetonitrile (10 ml) and the mixture was stirred for 20 minutes. The reaction mixture was poured into ice water and basified with an 8 N aqueous solution of sodium hydroxide. The product was extracted twice with ethyl acetate. The combined extracts were washed with an aqueous saturated solution of sodium hydrogen carbonate, dried on magnesium sulfate, filtered, and then concentrated under reduced pressure. The residue was dissolved into ethanol (20 ml) and palladium-carbon (59.9 mg) was added into the solution, then the mixture was stirred at 60° C. for 18 hours under a hydrogen atmosphere. The reaction mixture was cooled down to room temperature, filtered to remove insoluble materials, and then concentrated under reduced pressure. The residue was subjected to column chromatography (on Chromatorex NHDM1020 (trade name, manufactured by Fuji Silysia Chemical Ltd.); hexane-ethyl acetate 3:1) to obtain 402.0 mg (83% yield) of the title compound. Melting point: 123-124° C. (Hexane).

Provenance & Evidence