反应详情

To a cold solution (ice water bath) of the compound (346 g, 1.48 mol) prepared in Example 5 in CH2Cl2 (4.2 L), was added AlCl3 (984.6 g, 7.38 mol) portionwise under argon such that the reaction temperature was maintained below 10° C. The light brown suspension was stirred for 10 min, then EtSH (546 mL, 7.38 mol) was added dropwise at such a rate that the reaction temperature was maintained below 5° C. After 2.5 h of stirring below 10° C., the reaction mixture was slowly poured into 6 L ice water with strong agitation. The organic layer was separated, and the aqueous layer was extracted with CH2Cl2 (3×1 L). The combined CH2Cl2 layers were washed with water (2×1 L), then dried over Na2SO4. The solvent was removed under reduced pressure, giving a brown oil, which was filtered through a pad of silica gel (eluted with 0-10% EtOAc/Hexanes). Fractions were collected, and the title compound (314 g, 96%) was obtained as a thick yellow oil after solvent removal and vacuum drying. 1H NMR (CDCl3) 6.92 (d, 1H), 6.62 (d, 1H), 6.55 (dd, 1H), 4.10 (q, 2H), 3.43 (q, 1H), 2.75 (m, 2H), 2.64 (dd, 1H), 2.31 (dd, 1H), 2.29 (m, 1H), 1.67 (m, 1H), 1.20 (t, 3H). MS (CI) m/z 221 [M+H]+.

1. temperaturewas maintained below 10° C
2. temperaturewas maintained below 5° C
3. stirringAfter 2.5 h of stirring below 10° C.
4. customThe organic layer was separated
5. extractionthe aqueous layer was extracted with CH2Cl2 (3×1 L)
6. washThe combined CH2Cl2 layers were washed with water (2×1 L)
7. dry with materialdried over Na2SO4
8. customThe solvent was removed under reduced pressure
9. customgiving a brown oil, which
10. filtrationwas filtered through a pad of silica gel (eluted with 0-10% EtOAc/Hexanes)
11. customFractions were collected