Reaction #1121775

Reaction equation

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

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

thiophenol

sodium hydride

→

title compound 18a

Yield 70.0%

2-Amino-5-(4-methoxyphenyl)-3-phenylthiopyrazine

Yield 70.0%

Solvents

DMF

Conditions

Workup

1. 1
   Temperaturethe mixture refluxed for 6 h
2. 2
   Temperaturecooled
3. 3
   Extractionextracted with EtOAc
4. 4
   WashThe organic layer was washed with water
5. 5
   Dryingdried over Na2SO4
6. 6
   Filtrationfiltered
7. 7
   Otherthe solvent removed under reduced pressure
8. 8
   Otherto get a crude that
9. 9
   Otherwas purified by flash chromatography

Procedure

To a cooled solution of thiophenol (0.08 mL, 0.7 mmol) in dry DMF (10 mL), sodium hydride (NaH) (0.025 g, 1.00 mmol) was added and the resulting mixture was stirred for 15 min at 5-10° C. After this time 2-amino-3-bromo-5-(4-methoxyphenyl)pyrazine 17a (0.20 g, 0.71 mmol) was added and the mixture refluxed for 6 h, cooled and extracted with EtOAc. The organic layer was washed with water, dried over Na2SO4, filtered and the solvent removed under reduced pressure to get a crude that was purified by flash chromatography using petroleum ether-EtOAc (65:45 v/v) as eluent, to obtain 0.15 g of the title compound 18a as an orange solid (mp 89-90° C., 70% yield). 1H-NMR (CDCl3): 3.81 (s, 3H), 4.90 (br s, 2H), 6.89 (d, J=8.7, 2H), 7.33-7.39 (m, 7.45-7.50 (m, 2H), 7.69 (d, J=8.7, 2H), 8.28 (s, 1H). MS (ESI): m/z 310 (M+H+).

Source