Ethyl cyanoformate → Diethyl 4-bromophenylmalonate

Temperatur

-78 °C

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).

1. temperatureto warm to room temperature
2. stirringAfter stirring for 48 h at room temperature
3. customthe mixture was quenched with water (10 mL)
4. customThe reaction was partitioned between 1 N HCl (50 mL) and dichloromethane (50 mL)
5. customthe organic layer was separated
6. washThe organic layer was washed with 1 N HCl (50 mL)
7. dry with materialdried over Na2SO4
8. customevaporated
9. customThe crude material was purified by silica gel chromatography
10. washeluting with 0-20% ethyl acetate in hexanes

ORD-Eintrag

ord-31ba6dcbbf544dd08ba6af0ae574ad1d

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08524767B2