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

Temperature

80 °C

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)].

1. stirringthe mixture was stirred at 80° C. for 50 min
2. temperatureAfter this time the mixture was cooled to 0° C.
3. extractionThe mixture was extracted with EtOAc (2×100 mL)
4. washThe combined extracts were washed with brine (3×100 mL)
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. customevaporated in vacuo
8. customThe resulting residue was purified by column chromatography (0 to 100% gradient of DCM-MeOH—NH4OH (89:9:1) in DCM)

ORD record

ord-00a2f7b57be749289876b640c887913a

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08765940B2