Reaction #304446

Reaction equation

methyl 3-methylthiophene-2-carboxylate

N-Bromosuccinimide

azobis-isobutyronitrile

→

Intermediate

Yield 68.6%

Methyl 3-(bromomethyl)thiophene-2-carboxylate

Yield 68.6%

Solvents

carbon tetrachloride

Conditions

Workup

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

Procedure

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).

Source