反応 #1121774

反応方程式

2-amino-5-(4-mcthoxyphenyl)pyrazinc

2-Amino-5-(4-methoxyphenyl)pyrazine

pyridine

bromine

→

17a

収率 70.0%

2-Amino-3-bromo-5-(4-methoxyphenyl)pyrazine

収率 70.0%

溶媒

chloroform

chloroform

反応条件

後処理

1. 1
   洗浄the reaction mixture was washed with water
2. 2
   乾燥the organic layer dried over Na2SO4
3. 3
   ろ過filtered
4. 4
   その他the solvent was removed under reduced pressure
5. 5
   その他The crude product was purified by flash chromatography

実験手順

To a solution of 2-amino-5-(4-mcthoxyphenyl)pyrazinc 16a (0.35 g, 1.7 mmol) and pyridine (0.20 mL, 2.6 mmol) in chloroform (20 mL), bromine (Br2) (0.13 mL, 2.6 mmol) was added dropwise in chloroform (3 mL) at −10° C. After 6 h stirring at room temperature, the reaction mixture was washed with water, the organic layer dried over Na2SO4, filtered and the solvent was removed under reduced pressure. The crude product was purified by flash chromatography using dichloromethane-EtOAc (90:10 v/v) as eluent, to obtain 0.33 g of 17a as an brown solid (mp 166-170° C., 70% yield). 1H-NMR (CDCl3): 3.83 (s, 3H), 5.04 (br s, 2H), 6.92-6.96 (m, 2H), 7.76-7.80 (m, 2H), 8.31 (s, 1H). GC-MS (EI): m/z 279,281 (M1, 100).

出典