Cesium carbonate → 6-bromo-1'-[(2R)-tetrahydrofuran-2-ylmethyl]spiro[1-benzofuran-3,3'-indol]-2'(1'H)-one

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of 6-bromospiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (1.3 g, 4.3 mmol) in 2-butanone (40.0 mL) was added cesium carbonate (4.2 g, 12.9 mmol) and (R)-(tetrahydrofuran-2-yl)methyl 4-methylbenzenesulfonate (1.4 g, 5.4 mmol). The reaction was refluxed for 16 h, filtered and concentrated in vacuo to dryness. The residue was purified by flash chromatography with 25% ethyl acetate in hexanes to afford 6-bromo-1′-[(2R)-tetrahydrofuran-2-ylmethyl]spiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (1.75 g, 100%) as a colorless solid: MS (ES+) m/z 400.0 (M+1), 402.0 (M+1).

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