反应详情

Succinic anhydride (11.45 g, 0.11 mole) was dissolved in 1,2-dichloroethane (300 ml) and AlCl3 (50.76 g, 0.38 mole) was added under N2. The resulting mixture was stirred for 3 hours at room temperature, cooled to 0° C. and the compound from Step A (13 g, 0.03 mole), dissolved in 1,2-dichloroethane, was added slowly. The reaction mixture was kept at 5° C. for 3 days, then poured on ice, stirred for one hour and the two phases separated by decanting. The aqueous phase was extracted several times with CH2Cl2 (600 ml total). The organic phases were combined, washed with water, dried (MgSO4) and evaporated to dryness to yield the title compound as the free acid which then was converted to the methyl ester in conventional manner by treating the acid with methanol and anhydrous HCl. The ester had the following analysis: calculated: C, 63.27; H, 4.70; S, 6.50; observed: C, 63.19; H, 4.81; S, 6.63.

1. temperaturecooled to 0° C.
2. additionwas added slowly
3. waitThe reaction mixture was kept at 5° C. for 3 days
4. additionpoured on ice
5. stirringstirred for one hour
6. customthe two phases separated
7. customby decanting
8. extractionThe aqueous phase was extracted several times with CH2Cl2 (600 ml total)
9. washwashed with water
10. dry with materialdried (MgSO4)
11. customevaporated to dryness