反应详情

A solution of lithium hydroxide monohydrate (0.18 g, 4.36 mmol) in water (10.5 ml) was added dropwise to a solution of the methyl 6-[4-methoxy-2-methyl-3-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1H-xanthen-9-yl)phenyl]pyridine-2-carboxylate produced in Example 4-3 (1.05 g, 1.98 mmol) in THF (21 ml) at room temperature, and the mixture thus obtained was then stirred at the same temperature as above for 3 hours. Thereafter, water was added to the reaction solution, and the mixed solution was then washed with diethyl ether. Thereafter, a 1 N aqueous solution of hydrochloric acid (4.36 ml) was added to the water layer, and the mixed solution was then extracted with dichloromethane. The organic layer thus obtained was dried over anhydrous sodium sulfate. The solvent was distilled away under reduced pressure, and the residue thus obtained was then washed with a mixed solution of diethyl ether and hexane, followed by collection by filtration and drying, to obtain the title compound (0.75 g, yield: 73%).

1. customthe mixture thus obtained
2. washthe mixed solution was then washed with diethyl ether
3. additionThereafter, a 1 N aqueous solution of hydrochloric acid (4.36 ml) was added to the water layer
4. extractionthe mixed solution was then extracted with dichloromethane
5. customThe organic layer thus obtained
6. dry with materialwas dried over anhydrous sodium sulfate
7. distillationThe solvent was distilled away under reduced pressure
8. customthe residue thus obtained
9. washwas then washed with a mixed solution of diethyl ether and hexane
10. filtrationfollowed by collection by filtration
11. customdrying