Sodium hydride → 5-Bromo-3-(2,6-dichloro-benzyloxy)-pyrazin-2-ylamine

To an ice cooled solution of (2,6-dichloro-phenyl)-methanol (5 g, 28.2 mmol) in anhydrous tetrahydrofuran (200 mL) was added sodium hydride (1.13 g, 28.2 mmol, 60% disp.) slowly under nitrogen atmosphere. After stirring for 30 minutes, 3,5-dibromo-pyrazin-2-ylamine (7.08 g, 28.2 mmol) in anhydrous tetrahydrofuran (50 mL) was added via an addition funnel. Once the addition was complete the ice bath was removed and the reaction was refluxed under nitrogen and monitored by reversed phase HPLC. After 18 hr HPLC showed that the majority of the starting 3,5-dibromo-pyrazin-2-ylamine had been consumed and the reaction was allowed to cool to room temperature. The reaction mixture was concentrated in vacuum until 50 mL remained. The mixture was diluted with ethyl acetate (200 mL) and extracted with 50% brine (2×200 mL). The organic layer was dried over anhydrous magnesium sulfate and concentrated in vacuum. The crude product was purified using a silica gel column eluting with 1:1 ethyl acetate/dichloromethane to yield 5-bromo-3-(2,6-dichloro-benzyloxy)-pyrazin-2-ylamine as a white solid (8.17 g, 83% yield).

1. additionOnce the addition
2. customwas removed
3. temperaturethe reaction was refluxed under nitrogen
4. waitAfter 18 hr HPLC showed that the majority of the starting 3,5-dibromo-pyrazin-2-ylamine
5. customhad been consumed
6. concentrationThe reaction mixture was concentrated in vacuum until 50 mL
7. additionThe mixture was diluted with ethyl acetate (200 mL)
8. extractionextracted with 50% brine (2×200 mL)
9. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
10. concentrationconcentrated in vacuum
11. customThe crude product was purified
12. washeluting with 1:1 ethyl acetate/dichloromethane

ORD-Eintrag

ord-94ec18465e7547f8bc49d4e5a82ea336

Quelldatensatz

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08106197B2