Reaktion #171073

Reaktionsgleichung

AIBN

ethyl 3-chloro-5-fluoro-4-methylbenzoate

NBS

→

ethyl 4-(bromomethyl)-3-chloro-5-fluorobenzoate

Ausbeute 49.0%

Lösungsmittel

H2O

CCl4

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling
2. 2
   Waschenwashed with DCM (2×)
3. 3
   TrocknenThe combined extracts were dried (Na2SO4)
4. 4
   Einengenconcentrated
5. 5
   Sonstigepurified by flash chromatography (12% EtOAc/Hex)

Vorschrift

To a solution of ethyl 3-chloro-5-fluoro-4-methylbenzoate (5.3 g, 24.46 mmol) in CCl4 (100 mL) was added NBS (4.79 g, 26.91 mmol) followed by AIBN (0.4 g, 2.45 mmol). The reaction mixture was heated at 80° C. overnight. After cooling, the reaction mixture was diluted with H2O and washed with DCM (2×). The combined extracts were dried (Na2SO4), concentrated and purified by flash chromatography (12% EtOAc/Hex) to yield ethyl 4-(bromomethyl)-3-chloro-5-fluorobenzoate (3.53 g, 49%) as a light yellow solid. 1H NMR (400 MHz, DMSO-d6) δ 7.96-7.85 (m, 1H), 7.83 (dd, J=9.6, 1.5 Hz, 1H), 4.80 (t, J=5.7 Hz, 2H), 4.41 (q, J=7.1 Hz, 2H), 3.47 (s, 1H), 1.47-1.30 (m, 3H).

Quelle