Reacción #67477

Ecuación de reacción

ethyl cyanoformate

ethyl 2-(4-bromophenyl)acetate

lithium diisopropylamide

→

diethyl 2-(4-bromophenyl)malonate

Rendimiento 41.0%

Disolventes

THF

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturato warm to room temperature
2. 2
   workup.STIRRINGAfter stirring for 48 h at room temperature
3. 3
   Otrothe mixture was quenched with water (10 mL)
4. 4
   OtroThe reaction was partitioned between 1 N HCl (50 mL) and dichloromethane (50 mL)
5. 5
   Otrothe organic layer was separated
6. 6
   LavadoThe organic layer was washed with 1 N HCl (50 mL)
7. 7
   Secadodried over Na2SO4
8. 8
   Otroevaporated
9. 9
   OtroThe crude material was purified by silica gel chromatography
10. 10
    Lavadoeluting with 0-20% ethyl acetate in hexanes

Procedimiento

To a solution of ethyl 2-(4-bromophenyl)acetate (5.0 g, 21 mmol) in dry THF (40 mL) at −78° C. was added a 2.0M solution of lithium diisopropylamide in THF (11 mL, 22 mmol). After stirring for 30 minutes at −78° C., ethyl cyanoformate (2.0 mL, 21 mmol) was added and the mixture was allowed to warm to room temperature. After stirring for 48 h at room temperature, the mixture was quenched with water (10 mL). The reaction was partitioned between 1 N HCl (50 mL) and dichloromethane (50 mL), and the organic layer was separated. The organic layer was washed with 1 N HCl (50 mL), dried over Na2SO4 and evaporated. The crude material was purified by silica gel chromatography, eluting with 0-20% ethyl acetate in hexanes to give diethyl 2-(4-bromophenyl)malonate (2.6 g, 41%) 1H NMR (400 MHz, DMSO-d6) δ 7.60-7.58 (m, 2H), 7.36-7.34 (m, 2H), 5.03 (s, 1H), 4.21-4.09 (m, 4H), 1.20-1.16 (m, 6H).

Fuente