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

Participants

Reaction Steps

To a suspension of 4-bromo-2-phenoxybenzoic acid, 2a (35.1 g, 120 mmol) in. methylene chloride (350 mL) at 0° C. was added dropwise trifluoroacetic anhydride (20.3 mL, 144 mmol), and the reaction was stirred for 15 min. Boron trifluoride diethyl etherate (1.46 mL, 12.0 mmol) was added dropwise. The reaction became homogeneous upon stirring for 1 h at rt. The reaction was poured into 1 N NaOH, and the organic phase was dried over magnesium sulfate, filtered, and concentrated to give title compound 3-bromo-xanthen-9-one, 3a (32.14 g, 116 mmol). MS m/z (MH+) 275.

Provenance & Evidence