Spiro(1-benzopyran-2,4'-piperidin)-4(3H)-one--hydrogen chloride (1/1) → Spiro[chroman-2,4'-piperidine]

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Reaction Steps

To a stirred solution of the spiro[2H-1-benzopyran-2,4'-piperidin]-4(3H)-one, hydrochloride (53 mg, 0.21 mmol) in methanol (5 mL) at 0° C., was added sodium borohydride (38 mg, 1 mmol) in several portions. After 30 minutes the mixture was evaporated and then treated with concentrated hydrochloric acid (2 mL) for 30 min. Evaporation gave a residue which was hydrogenated with palladium on carbon (10%, 10 mg), H2 (1 atm) in ethanol for two hours. Filtration to remove the catalyst gave the crude intermediate (89 mg) which was used without further purification.

Provenance & Evidence