반응 #93720
ord-1de57efd666a4df18f058051071bcbfc
반응 방정식
반응물
시약
반응 조건
후처리
- 1기타prepared analogously to a method of Shimohigashi Y
- 2기타The resulting reaction mixture
- 3기타The dicyclohexylurea that has precipitated
- 4여과is filtered off with suction
- 5workup.ADDITIONthe filtrate is diluted with methylene chloride
- 6세척washed with water and phosphate buffer solution
- 7건조The organic phase is dried over sodium sulphate
- 8농축concentrated by evaporation
- 9기타the oily residue is chromatographed over silica gel
실험 절차
In succession, 2.76 g (10 mmol) of p-methoxybenzyl-tert.-butylthiomethylammonium chloride (Example 24), 2.06 g (10 mmol) of dicyclohexyl carbodiimide and, dropwise, 1.40 ml (10 mmol) of triethylamine are added at room temperature to a solution of 1.83 g (10 mmol) of 2-(S)-bromo-3-(R)-hydroxybutyric acid prepared analogously to a method of Shimohigashi Y. et al., Bull. Chem. Soc. Japan 52, 949 (1979). The resulting reaction mixture is stirred at room temperature for 2 hours. The dicyclohexylurea that has precipitated is filtered off with suction and the filtrate is diluted with methylene chloride and washed with water and phosphate buffer solution having a pH of 8. The organic phase is dried over sodium sulphate and concentrated by evaporation and the oily residue is chromatographed over silica gel using toluene/ethyl acetate. The title compound is obtained in the form of a colourless, viscous oil.