反应详情

温度

50 °C

1.61 mL of cyclopentanecarboxylic acid was dissolved in 5 mL of tetrahydrofuran, and this mixture was added dropwise to 50 mL of solution of lithium diisopropylamide in tetrahydrofuran prepared from 20.9 mL of n-butyllithium in n-hexane (1.56 M) and 4.58 mL of diisopropylamine at −30° C., and then this mixture was stirred for one hour at 50° C. and for another one hour at room temperature. After the reaction mixture was cooled to −30° C., a solution of 5.00 g of methyl 4-(bromomethyl)-2-methoxybenzoate in 5 mL of tetrahydrofuran was added dropwise to this mixture, which was then stirred for 1.5 hours at −10° C. and for another 1.5 hours at room temperature. A saturated aqueous solution of ammonium chloride and diethyl ether were successively added to the reaction mixture, and the organic phase was separated therefrom. A saturated aqueous solution of sodium hydrogen carbonate was added to the resultant organic phase, from which an aqueous phase was separated, followed by adjustment to pH 2 with 6M hydrochloric acid, and then the organic layer was separated therefrom by adding chloroform thereto. After the resultant organic phase was washed with water and a saturated sodium chloride solution successively, the washed phase was dried over anhydrous magnesium sulfate, and the solvent was distilled out under reduced pressure. The resultant residue was purified by silica gel column chromatography [eluent; hexane:ethyl acetate=3:2] to yield 0.718 g of 1-[3-methoxy-4-(methoxycarbonyl)benzyl]-cyclopentanecarboxylic acid as colorless oil.

1. temperatureAfter the reaction mixture was cooled to −30° C.
2. stirringwas then stirred for 1.5 hours at −10° C. and for another 1.5 hours at room temperature
3. customthe organic phase was separated
4. additionA saturated aqueous solution of sodium hydrogen carbonate was added to the resultant organic phase
5. customfrom which an aqueous phase was separated
6. customthe organic layer was separated
7. additionby adding chloroform
8. washAfter the resultant organic phase was washed with water
9. dry with materiala saturated sodium chloride solution successively, the washed phase was dried over anhydrous magnesium sulfate
10. distillationthe solvent was distilled out under reduced pressure
11. customThe resultant residue was purified by silica gel column chromatography [eluent; hexane:ethyl acetate=3:2]