Sodium Hydroxide → 6-Bromo-1,2-dihydrospiro(indole-3,4'-oxane)

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Reaction Conditions

Reaction Steps

A heterogeneous mixture of 6-bromo-2′,3′,5′,6′-tetrahydrospiro[indoline-3,4′-pyran]-2-one (3.5 g, 12.4 mmol) in toluene (25 mL) was stirred at 80° C. To the heated mixture was added a solution of Red-Al (65% in toluene, 11.6 mL, 37.2 mmol) and the mixture was stirred at 80° C. for 50 min. After this time the mixture was cooled to 0° C. and quenched with a 2 N solution of aqueous NaOH (31 mL, 62 mmol). The mixture was extracted with EtOAc (2×100 mL). The combined extracts were washed with brine (3×100 mL), dried over Na2SO4, filtered, and evaporated in vacuo. The resulting residue was purified by column chromatography (0 to 100% gradient of DCM-MeOH—NH4OH (89:9:1) in DCM) to give 6-bromo-2′,3′,5′,6′-tetrahydrospiro[indoline-3,4′-pyran] as a yellow solid. Mass Spectrum (ESI) m/e 268 [(M+1) (79Br)] and 270 [(M+1) (81Br)].

Provenance & Evidence