반응 #69491
ord-b8646e3abb5748fea955e38591076796
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후처리
- 1workup.STIRRINGthe mixture was stirred at room temperature overnight
- 2세척the THF layers was washed with water (2×350 mL)
- 3온도cooled to 0° C.
- 4기타equipped with a bleach trap
- 5기타formed
- 6workup.STIRRINGThe mixture was stirred at room temperature for 3 h
- 7workup.STIRRINGwas stirred at room temperature overnight
- 8추출The aqueous phase was extracted with DCM (2×)
- 9세척washed with brine
- 10건조dried over MgSO4
- 11여과filtered
- 12기타evaporated
- 13기타to afford an orange solid
- 14기타This solid was triturated in diethyl ether
- 15여과filtered
- 16기타dried
실험 절차
To a suspension of methyl 3-acetyl-5-bromo-4-hydroxybenzoate (70 g, 243.52 mmol) in THF (700 mL) at −50° C. under nitrogen (flask equipped with a bleach trap) was added lithium bis(trimethylsilyl)amide (828 ml, 828 mmol). The dark solution was allowed to warm to −5° C. and stirred for 2 h. Carbon disulfide (22 mL, 365 mmol) was added in one portion to the solution at −20° C. then the mixture was stirred at room temperature overnight. Water (700 mL) was added, the THF layers was washed with water (2×350 mL). The aqueous phases were combined and cooled to 0° C. and quenched with H2SO4 (108 ml, 1948 mmol) in a vessel equipped with a bleach trap to neutralize the H2S formed. The mixture was stirred at room temperature for 3 h, DCM was added (700 mL) and mixture was stirred at room temperature overnight. The aqueous phase was extracted with DCM (2×). The organic phases were combined, washed with brine, dried over MgSO4, filtered and evaporated to afford an orange solid. This solid was triturated in diethyl ether, filtered and dried to give methyl 8-bromo-4-hydroxy-2-thioxo-2H-chromene-6-carboxylate (48.7 g, 63%) as a yellow/orange solid. Mass Spectrum: m/z [M+H]+=317.