反应详情

892 mg (5.5 mmol) of carbonyldiimidazole (CDl) were added to a solution of 830 mg (5 mmol) of 1-hydroxymethyladamantane in 10 ml of tetrahydrofuran and the mixture was stirred overnight at RT. It was then treated with 1 g (2.57 mmol) of tertbutyl (2S)-2-amino-3-(4-(3-ethoxycarbonyl-propyloxy)phenyl)propionate and 442 μl (2.57 mmol) of diisopropylethylamine (DIPEA) and the mixture was stirred overnight at 50° C. After cooling, it was taken up in ethyl acetate and the organic phase was washed successively with 3% strength citric acid solution, sodium hydrogencarbonate solution, 3×H2O and saturated NaCl solution. The organic phase was dried using MgSO4, the drying agent was filtered off and the filtrate was concentrated. The residue was chromatographed on silica gel using CH2Cl2/CH3OH (99/1). 1.19 g (85%) of an oil were obtained, which was employed without further purification for the synthesis of (4.4).

1. stirringthe mixture was stirred overnight at 50° C
2. temperatureAfter cooling
3. washthe organic phase was washed successively with 3% strength citric acid solution, sodium hydrogencarbonate solution, 3×H2O and saturated NaCl solution
4. customThe organic phase was dried
5. filtrationthe drying agent was filtered off
6. concentrationthe filtrate was concentrated
7. customThe residue was chromatographed on silica gel