Reaktion #304446

Reaktionsgleichung

methyl 3-methylthiophene-2-carboxylate

N-Bromosuccinimide

azobis-isobutyronitrile

→

Intermediate

Ausbeute 68.6%

Methyl 3-(bromomethyl)thiophene-2-carboxylate

Ausbeute 68.6%

Lösungsmittel

carbon tetrachloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux under nitrogen
2. 2
   SonstigeThe reaction mixture was irradiated with a 500 W UV lamp for 1.5 hours
3. 3
   Filtrationfiltered under autocup 0.45 μm
4. 4
   Sonstigefollowed by the evaporation of the filtrate
5. 5
   SonstigeThe residue was purified by chromatography on silica gel (eluent

Vorschrift

A mixture of methyl 3-methylthiophene-2-carboxylate (13.2 mmol), N-Bromosuccinimide (13.2 mmol) and a catalytic amount of azobis-isobutyronitrile in carbon tetrachloride were heated at reflux under nitrogen. The reaction mixture was irradiated with a 500 W UV lamp for 1.5 hours, cooled down to room temperature and then filtered under autocup 0.45 μm, followed by the evaporation of the filtrate. The residue was purified by chromatography on silica gel (eluent: stepwise gradient of 3-5% diethyl ether in petroleum ether) to give 2.13 g of Intermediate IV.1 (69%), which was characterized by 1H NMR (CDCl3, 400 MHz) δ (ppm) 3.90 (s, 3H), 4.92 (s, 2H), 7.18 (d, J=5.3 Hz, 1H), 7.47 (d, J=5.3 Hz, 1H).

Quelle