تفاعل #1885052

معادلة التفاعل

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

المردود 96.0%

المذيبات

1,2-dichloroethane

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةAfter cooling to 0° C. the reaction mixture
2. 2
   أخرىwas quenched by the careful addition of saturated aqueous NaHCO3 (100 mL)
3. 3
   أخرىThe phases were separated
4. 4
   استخلاصthe aqueous phase was extracted with dichloromethane (2×100 mL)
5. 5
   تجفيفThe combined organic extracts were dried over MgSO4
6. 6
   تركيزconcentrated under reduced pressure

الإجراء التجريبي

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.

المصدر