Cesium carbonate → (3-Bromo-5-oxo-5,6,7,8-tetrahydro-naphthalen-1-yloxy)-acetic acid tert-butyl ester

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Reaction Steps

To a suspension of 7-bromo-5-hydroxy-3,4-dihydro-2H-naphthalen-1-one (XIb, 158 mg, 0.65 mmol) and cesium carbonate (431 mg, 1.31 mmol) in acetonitrile (5 mL) was added tert-butyl bromoacetate (XII, 261 mg, 1.31 mmol) at room temperature under nitrogen. The resulting suspension was stirred for 15 h at room temperature and then concentrated under vacuum. The residue was diluted with water (10 mL) and ethyl acetate (20 mL). The aqueous layer was separated and extracted with ethyl acetate (20 mL), and the combined organic extracts were washed with brine solution (50 mL), then dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo to give the crude product. Chromatography using an ISCO (40 g) column, (gradient elution with 5-25% ethyl acetate in hexanes) provided (3-bromo-5-oxo-5,6,7,8-tetrahydro-naphthalen-1-yloxy)-acetic acid tert-butyl ester (150 mg, 64%) as a white solid: ES(+)-HRMS m/e calcd. for C16H19O4Br (M+Na)+377.0359, obsd. 377.0358.

Provenance & Evidence