Boron Trichloride → 7-hydroxy-3-(4-methoxyphenyl)-2H-1-benzopyran

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Reaction Steps

To a stirred solution of compound 1 (0.2 g, 0.58 mmol) in dry CH2Cl2 (4 mL), a solution of BCl3 (1 M, 0.7 mL, 0.7 mmol) in CH2Cl2 was added dropwise at 0° C. under nitrogen. After stirring for 10 min, the mixture was quenched with ice water and a saturated NaHCO3 solution (10 mL), and then stirred for a further 20 min. After extraction with CH2Cl2 (15 mL×6), the organic layers were combined, washed with brine, and dried with anhydrous MgSO4. After filtration, the filtrate was concentrated in vacuo, followed by purification via silica gel column chromatography (ethyl acetate/n-hexane=1:4), thus giving the title compound 2b as a colorless crystal (0.12 g, 81% yield).

Provenance & Evidence