7-bromo-4-fluoro-2-methoxy-9H-xanthen-9-one → 7-bromo-4-fluoro-2-methoxy-9-methyl-9H-xanthen-9-ol

HRID 335915

Reaction equation

[Br:1][C:2]1[CH:15]=[C:14]2[C:5]([O:6][C:7]3[C:8]([F:19])=[CH:9][C:10]([O:17][CH3:18])=[CH:11][C:12]=3[C:13]2=[O:16])=[CH:4][CH:3]=1.[CH3:20][Mg]Cl>C1COCC1>[Br:1][C:2]1[CH:15]=[C:14]2[C:5]([O:6][C:7]3[C:8]([F:19])=[CH:9][C:10]([O:17][CH3:18])=[CH:11][C:12]=3[C:13]2([CH3:20])[OH:16])=[CH:4][CH:3]=1

Participants

Conditions

Temperature: -30 °C

Procedure

7-bromo-4-fluoro-2-methoxy-9H-xanthen-9-one (22 g, 68.1 mmol) was dissolved in 300 ml of THF and cooled to −30° C. in a dry ice ACN bath. Methylmagnesium chloride (34.0 mL, 102 mmol) (3M in THF) was added to the slurry maintaining temperature less than −15° C. The solution was allowed to warm to RT (undissolved solids went into solution), then quenched with saturated NH4Cl (250 mL). The aqueous layer was extracted with EtOAc (3×200 mL) and the combined organic layers were washed with brine and dried over anhydrous sodium sulfate, filtered and concentrated to afford 7-bromo-4-fluoro-2-methoxy-9-methyl-9H-xanthen-9-ol as a brown liquid that was used without further purification.

Workup

temperaturemaintaining temperature less than −15° C
temperatureto warm to RT (undissolved solids went into solution)
customquenched with saturated NH4Cl (250 mL)
extractionThe aqueous layer was extracted with EtOAc (3×200 mL)
washthe combined organic layers were washed with brine
dry with materialdried over anhydrous sodium sulfate
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-6a8d8e9f9362467796036fcc222f81eb
Source dataset: uspto-grants-2014_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08883782B2

Linked notes

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