Boron trifluoride etherate → 3-Bromo-9H-xanthen-9-one

Participants

Reaction Steps

To a suspension of 4-bromo-2-phenoxy-benzoic acid (35.1 g, 120 mmol) in CH2Cl2 (350 mL) at 0° C. was added trifluoroacetic anhydride (20.3 mL, 144 mmol), dropwise, and the reaction was stirred for 15 min. At that time, boron trifluoride diethyl etherate (1.46 mL, 12.0 mmol) was added, dropwise. The reaction became homogeneous upon stirring for 1 h at room temperature. Upon completion, the reaction was poured into 1 N NaOH, and the organic phase was dried over magnesium sulfate, filtered, and concentrated to give Compound 3a (32.14 g, 116 mmol). MS m/z (MH+) 275.

Provenance & Evidence