Reaktion #1121774

Reaktionsgleichung

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

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

pyridine

bromine

→

17a

Ausbeute 70.0%

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

Ausbeute 70.0%

Lösungsmittel

chloroform

chloroform

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenthe reaction mixture was washed with water
2. 2
   Trocknenthe organic layer dried over Na2SO4
3. 3
   Filtrationfiltered
4. 4
   Sonstigethe solvent was removed under reduced pressure
5. 5
   SonstigeThe crude product was purified by flash chromatography

Vorschrift

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).

Quelle