反应详情

10 g of dimethyl 1,2,3,6-tetrahydro-phthalate (II) was treated at -5° C. with 25 ml of acetic anhydride in the presence of 9 ml of tin tetrachloride. The reaction mixture was poured into iced water and extracted with diethyl ether. The organic phase was washed with a saturated aqueous solution of sodium bicarbonate and then with water, and was then evaporated to dryness under vacuum. The obtained oil was dissolved in benzene, treated with a methanolic solution of hydrogen chloride. The solution was evaporated to dryness and the residue was purified by chromatography on column of silica gel to give 9 g of the title compound in 75% overall yield.

1. extractionextracted with diethyl ether
2. washThe organic phase was washed with a saturated aqueous solution of sodium bicarbonate
3. customwith water, and was then evaporated to dryness under vacuum
4. dissolutionThe obtained oil was dissolved in benzene
5. additiontreated with a methanolic solution of hydrogen chloride
6. customThe solution was evaporated to dryness
7. customthe residue was purified by chromatography on column of silica gel