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) δ 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 (Cl) 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