反应详情

To a solution of (E)-3-{[1-(ethoxycarbonylmethyl)-1H-imidazol-5-yl]methylidene}-1-(triphenylmethyl)piperidin-4-ol (560 mg) in N,N-dimethylformamide (5 ml) were added N,N-dimethylformamide dineopentyl acetal (2.5 ml) and thioacetic acid (0.6 ml) at room temperature. After being stirred at the same temperature for 1.5 hour, the mixture was partitioned between ethyl acetate and water. The organic layer was separated, washed with a saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. Solvents were removed under reduced pressure, and residue was purified by silica gel chromatography using hexane, ethyl acetate, and dichloromethane (1:2:2) as an eluent. In a separate run, further starting material (E)-3-{[1-(ethoxycarbonylmethyl)-1H-imidazol-5-yl]methylidene}-1-(triphenylmethyl)piperidin-4-ol (1.0 g) was subjected to the similar reaction/purification procedure. Both products were combined to afford an approximately 5:2 mixture of (E)-4-(acetylsulfanyl)-3-{[1-(ethoxycarbonylmethyl)-1H-imidazol-5-yl]methylidene}-1-(triphenylmethyl)piperidine and 5-{(acetylsulfanyl)[1-(ethoxycarbonylmethyl)-1H-imidazol-5-yl]methyl}-1-(triphenylmethyl)-1,2,3,6-tetrahydropyridine (500 mg, gross yield: 29%), as a yellow amorphous solid.

1. customthe mixture was partitioned between ethyl acetate and water
2. customThe organic layer was separated
3. washwashed with a saturated aqueous sodium chloride solution
4. dry with materialdried over anhydrous magnesium sulfate
5. customSolvents were removed under reduced pressure, and residue
6. customwas purified by silica gel chromatography
7. customwas subjected to the similar reaction/purification procedure
8. customto afford