反应详情

A solution of 1 g (5 mmol) of 5-(tert-butyl)-2-methylfuran-3-carbonyl chloride (Maybridge, Cornwall, UK) dissolved in dry acetonitrile (4 mL) and 6.25 mL (12.5 mmol) of 2 M trimethylsilyldiazomethane in hexanes (Aldrich, Milwaukee, Wis.) was stirred 1.75 h at room temperature and the mixture was cooled on an ice bath for 5 min. To this, 30% hydrogen bromide in acetic acid (2 mL, 10 mmol) was added dropwise over 10 min. This was stirred an additional 20 minutes on an ice bath. Evaporation of the solvents gave 1-[5-(tert-butyl)-2-methyl(3-furyl)]-2-bromoethan-1-one (1 g, 77%) as a brown oil. 1H-NMR (DMSO-d6; 300 MHz) δ6.50 (s, 1H), 4.57(s, 2H), 2.52 (s, 1H), 1.24 (s, 9H). Mass spectrum (LCA, m/z): Calcd. for C11H15O2Br, 259.1 and 261.1 (M+H), found 259.1 and 261.1.

1. temperaturethe mixture was cooled on an ice bath for 5 min
2. customEvaporation of the solvents