反应详情

Powdered anhydrous aluminum chloride (0.78 g) was slowly added to a stirred mixture of 1,2-dimethoxybenzene (0.64 g, 4.66 mmol) and 3,4-dimethoxyphenylacetyl chloride (1.0 g, 4.66 mmol) in 10 mL freshly distilled dry dichloromethane. An exothermic reaction occurred. The orange solution became brown as the mixture refluxed. The reaction mixture was heated to reflux for an additional 2 h and then allowed to cool to room temperature. The cooled solution was poured into a mixture containing of 5 g crushed ice and 5.5 mL 7.5 N HCl. The organic phase was separated and the aqueous phase was extracted three times with 10 mL dichloromethane. The combined dichloromethane extract was dried (Na2SO4), filtered, and evaporated to give a white solid, which was crystallized from ethanol to give pure white needles of 11a in 98% yield; mp 105-107° C. (lit.30 mp 104-106° C.); 1H NMR δ 3.85 (s, 6H), 3.91 (s, 3H), 3.94 (s, 3H), 4.18 (s, 2H), 6.81 (m, 2H), 6.91 (m, 2H), 7.56 (d, 1H, J=2.0), 7.66 (dd, 1H, J=8.4,2.0); 13C NMR δ 45.2, 56.3, 56.4, 56.5, 110.4, 111.1, 111.8, 112.8, 121.3, 121.9, 123.9, 127.9, 130.2, 148.4, 149.5, 153.8, 197.0.

1. distillationfreshly distilled dry dichloromethane
2. customAn exothermic reaction
3. temperaturerefluxed
4. temperatureThe reaction mixture was heated
5. temperatureto reflux for an additional 2 h
6. additionThe cooled solution was poured into a mixture
7. additioncontaining of 5 g
8. customThe organic phase was separated
9. extractionthe aqueous phase was extracted three times with 10 mL dichloromethane
10. extractionThe combined dichloromethane extract
11. dry with materialwas dried (Na2SO4)
12. filtrationfiltered
13. customevaporated
14. customto give a white solid, which
15. customwas crystallized from ethanol