Hydrochloric Acid → HCID 21107217, compound

Participants

Reaction Steps

A solution of 6-bromo-4,4-dimethyl-chroman-2-one (U.S. Pat. No. 6,252,090, 4 g, 15.7 mmol) in anhydrous tetrahydrofuran (20 mL) was treated with a 3M solution of ethyl magnesium bromide (10.5 mL, 31.5 mmol) and stirred at ambient temperature for 2 h. The reaction mixture was poured into cold dilute hydrochloric acid and extracted with ethyl acetate (×2). The combined organic extract was dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to afford a residue which was dissolved in 50 mL of benzene, treated with p-toluene sulfonic acid (1 g, 3.92 mmol) and the resulting reaction mixture was refluxed overnight. The reaction mixture cooled to ambient temperature, filtered on silica gel and washed with 10% ethyl acetate in hexane. The filtrate and washings were evaporated in vacuo to an oil which was subjected to flash column chromatography over silica gel (230-400 mesh) using 5% ethyl acetate in hexane as the eluent to afford the title compound as a pale yellow oil (3.9 g, 84%).

Provenance & Evidence