反应详情

To a stirred solution of ethyl 2-chlorophenoxyacetate (32.0 g, 149 mmol) in dichloromethane (75 mL) at ambient temperature under nitrogen was added succinic anhydride (22.4 g, 224 mmol). The reaction mixture was cooled in ice-water and to this was added portion wise aluminum trichloride (59.6 g, 447 mmol), whilst maintaining the temperature below 20° C. The reaction mixture was then allowed to stir at ambient temperature for 20 minutes and was then heated to reflux and stirred at this temperature for 3 hours. The reaction mixture was allowed to cool to ambient temperature, then poured into a mixture of ice, water (200 ml) and HCl (10 N, 100 ml). The two phase system was separated and the aqueous layer was extracted with ethyl acetate (5×100 mL). All organic layers were then combined and washed with water (2×100 mL), dried over Na2SO4, and concentrated under reduced pressure to give an orange oily solid. Hexane (300 mL) was added, and after standing at ambient temperature for 1 hour, the precipitate was filtered off and re-crystallized from ethyl acetate/hexane to give 9 as a light yellow powder (21.5 g, 46% yield, 98% pure by LCMS and 1H NMR), 1H NMR (400 MHz; CDCl3): δ 7.79 (m, 1H); 7.66 (m, 1H); 6.79 (m, 1H); 4.90 (s, 2H); 4.12 (q, 2H); 2.82 (m, 2H); 2.42 (m, 2H); 1.30 (t, 3H).

1. temperaturewhilst maintaining the temperature below 20° C
2. temperaturewas then heated
3. temperatureto reflux
4. stirringstirred at this temperature for 3 hours
5. temperatureto cool to ambient temperature
6. customThe two phase system was separated
7. extractionthe aqueous layer was extracted with ethyl acetate (5×100 mL)
8. washwashed with water (2×100 mL)
9. dry with materialdried over Na2SO4
10. concentrationconcentrated under reduced pressure
11. customto give an orange oily solid
12. waitafter standing at ambient temperature for 1 hour
13. filtrationthe precipitate was filtered off
14. customre-crystallized from ethyl acetate/hexane