反应 #1885052

反应方程式

3,5-difluoroaniline

(R)-2-(2,2-dimethyl-5-oxo-1,3-dioxolan-4-yl)acetaldehyde

acetic acid

sodium borohydride

→

(R)-5-[2-(3,5-difluorophenylamino)ethyl]-2,2-dimethyl-1,3-dioxolan-4-one

收率 96.0%

溶剂

1,2-dichloroethane

反应条件

后处理

1. 1
   温度After cooling to 0° C. the reaction mixture
2. 2
   其他was quenched by the careful addition of saturated aqueous NaHCO3 (100 mL)
3. 3
   其他The phases were separated
4. 4
   萃取the aqueous phase was extracted with dichloromethane (2×100 mL)
5. 5
   干燥The combined organic extracts were dried over MgSO4
6. 6
   浓缩concentrated under reduced pressure

实验过程

To a stirred solution of 3,5-difluoroaniline (4.0 g, 31.0 mmol), (R)-2-(2,2-dimethyl-5-oxo-1,3-dioxolan-4-yl)acetaldehyde (4.9 g, 31.0 mmol) and acetic acid (1.7 ml, 31.0 mmol) in 1,2-dichloroethane (100 mL) under nitrogen at 0° C. was added sodium borohydride (1.17 g, 31.0 mmol mol) in portions over 10 minutes. The resulting mixture was stirred at RT for 2.5 hours. After cooling to 0° C. the reaction mixture was quenched by the careful addition of saturated aqueous NaHCO3 (100 mL) followed by DCM (100 mL). The phases were separated and the aqueous phase was extracted with dichloromethane (2×100 mL). The combined organic extracts were dried over MgSO4 and concentrated under reduced pressure to provide the crude (R)-5-[2-(3,5-difluorophenylamino)ethyl]-2,2-dimethyl-1,3-dioxolan-4-one as a yellow oil (8.07 g, 29.7 mmol, 96% yield) which was used without any further purification in the next reaction step. LC/MS (10%-99% CH3CN (0.035% TFA)/H2O (0.05% TFA), m/z: M+1 obs=272.3; tR=1.76 min.

来源