反応 #304446

反応方程式

methyl 3-methylthiophene-2-carboxylate

N-Bromosuccinimide

azobis-isobutyronitrile

→

Intermediate

収率 68.6%

Methyl 3-(bromomethyl)thiophene-2-carboxylate

収率 68.6%

溶媒

carbon tetrachloride

反応条件

後処理

1. 1
   温度at reflux under nitrogen
2. 2
   その他The reaction mixture was irradiated with a 500 W UV lamp for 1.5 hours
3. 3
   ろ過filtered under autocup 0.45 μm
4. 4
   その他followed by the evaporation of the filtrate
5. 5
   その他The residue was purified by chromatography on silica gel (eluent

実験手順

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).

出典