反应 #2122523
ord-8c640b24d8654cc39733a0f73dd9ab82
反应方程式
反应条件
后处理
- 1温度while maintaining the temperature between −5° C. and 0° C
- 2workup.WAITstored in a freezer (−25° C.) for 14 hours
- 3其他thaw to ambient temperature
- 4洗涤washed with water (200 mL), 1N HCl (100 mL) and brine (100 mL)
- 5干燥dried (MgSO4)
- 6过滤filtered
- 7浓缩concentrated in vacuo
实验过程
A CH2Cl2 (200 mL) solution of p-toluenesulfonyl chloride (8.65 g, 45.4 mmol) was added dropwise to a cooled (−5° C.) CH2Cl2 (200 mL) solution of (S)-benzyl 2-hydroxy-2-phenylacetate (10.0 g, 41.3 mmol), triethylamine (5.75 mL, 41.3 mmol) and 4-dimethylaminopyridine (0.504 g, 4.13 mmol), while maintaining the temperature between −5° C. and 0° C. The reaction was stirred at 0° C. for 9 hours, and then stored in a freezer (−25° C.) for 14 hours. It was allowed to thaw to ambient temperature and washed with water (200 mL), 1N HCl (100 mL) and brine (100 mL), dried (MgSO4), filtered, and concentrated in vacuo to provide benzyl 2-phenyl-2-(tosyloxy)acetate as a viscous oil which solidified upon standing (16.5 g). The chiral integrity of the product was not checked and that product was used for the next step without further purification. 1H NMR (DMSO-d6, δ=2.5, 500 MHz) δ 7.78 (d, J=8.6, 2H), 7.43-7.29 (m, 10H), 7.20 (m, 2H), 6.12 (s, 1H), 5.16 (d, J=12.5, 1H), 5.10 (d, J=12.5, 1H), 2.39 (s, 3H). RT=3.00 (Cond. 3); >90% homogeneity index; LC/MS: Anal. Calcd. for [M+H]+ C22H20NaO5S: 419.09; found 419.04.