反应详情

Mechanically stir suspensions of 1-(2,4-dihydroxy-phenyl)-2-methyl-propan-1-one (818 g, 4.54 mol) in ethanol (3 L) and water (6 L) in two separate 22-L Morton flasks. Treat each suspension with potassium iodate (170 g, 794 mmol) and iodine (410 g, 1.62 mol) and allow to stir over night at room temperature. Dilute the mixtures with water (2 L), adjust pH to 4 by adding 5N hydrochloric acid, then extract twice with 4 L of ethyl acetate. Wash organic layers once with dilute aqueous sodium bisulfite, brine, dry with magnesium sulfate, filter, combine both filtrates, and evaporate to 2.6 Kg of a black solid. Chromatograph 500 g portions of the solid on 3.5 Kg of silica gel, eluting with 80% dichloromethane in heptane to provide the title compound (1357 g, 49% yield) in approximately 97% purity (HPLC shows 97% purity, with 3% 3,5-diiodo analog; LCMS confirms both. HPLC Rt=4.75 min; 1H NMR (CDCl3) δ 14.07 (s, 1H), 7.72 (d, J=8.0 Hz, 1H), 6.62 (d, J=8.0 Hz, 1H), 6.02 (s, 1H), 3.53 (hept, J=8.0 Hz, 1H), 1.24 (d, J=8.0 Hz, 6H); MS (m/z): 307.0 (M+1).

1. extractionextract twice with 4 L of ethyl acetate
2. dry with materialWash organic layers once with dilute aqueous sodium bisulfite, brine, dry with magnesium sulfate
3. filtrationfilter
4. customevaporate to 2.6 Kg of a black solid
5. washChromatograph 500 g portions of the solid on 3.5 Kg of silica gel, eluting with 80% dichloromethane in heptane