Reacción #1885052

Ecuación de reacción

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

Rendimiento 96.0%

Disolventes

1,2-dichloroethane

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaAfter cooling to 0° C. the reaction mixture
2. 2
   Otrowas quenched by the careful addition of saturated aqueous NaHCO3 (100 mL)
3. 3
   OtroThe phases were separated
4. 4
   Extracciónthe aqueous phase was extracted with dichloromethane (2×100 mL)
5. 5
   SecadoThe combined organic extracts were dried over MgSO4
6. 6
   Concentraciónconcentrated under reduced pressure

Procedimiento

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.

Fuente