反应详情

Anhydrous tetrahydrofuran (6 ml) is added to a mixture of t-butyl (2S)-2-[3-(2-cyclohexylethyl)-3-(2-hydroxyethyl)ureido]propionate (Compound No. 1-1, 1.0 g) and triphenylphosphine (1.5 g) under a nitrogen atmosphere, and the mixture is stirred for 30 minutes under salt-ice cooling. Diisopropyl azodicarboxylate (1.2 ml) is added dropwise to the mixture while keeping liquid temperature at 5° C., and then thioacetic acid (0.4 ml) is added dropwise thereto over 20 minutes. The mixture is stirred for 20 minutes, a 10% aqueous sodium hydrogencarbonate solution (30 ml) is added to the reaction mixture, and the whole is extracted with ether. The organic layer is washed with a 10% aqueous sodium hydrogencarbonate solution, water and saturated brine successively, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting oily matter is purified by silica gel column chromatography to give the titled compound (Compound No. 5-1).

1. customat 5° C.
2. extractionthe whole is extracted with ether
3. washThe organic layer is washed with a 10% aqueous sodium hydrogencarbonate solution, water and saturated brine successively
4. dry with materialdried over anhydrous magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. customThe resulting oily matter is purified by silica gel column chromatography