Lauroyl peroxide → tert-Butyl 8-bromo-2,3-diphenyl-7,8-dihydropyrido[2,3-b]pyrazine-5(6H)-carboxylate

Temperatur

60 °C

To a stirred solution of tert-Butyl 2,3-diphenyl-7,8-dihydropyrido[2,3-b]pyrazine-5(6H)-carboxylate (step 1)(25 g, 64.5 mmol) in carbon tetrachloride (645 ml) at RT under N2 was added NBS (13.78 g, 77 mmol) followed directly by lauroyl peroxide (0.257 g, 0.645 mmol) and the solution was heated at 60° C. for 4 h 15 mins. The mixture was filtered through filter paper and the filtrate was washed with sat. NaHCO3 (300 ml), 2 M Na2SO3 (300 ml) and sat. brine (300 ml). The solution was dried over MgSO4 and filtered, washing MgSO4 bed with DCM (100 ml). The solvent was removed in vacuo. The crude product was dissolved in diethyl ether (300 ml) and was allowed to stand at RT and placed in a fridge overnight. The resulting crystalline solid was isolated by decanting off the mother liquors. The crystals were washed with diethyl ether to afford the title compound. Further product was obtained by chromatography of the mother liquors eluting with iso-hexane/EtOAc to afford the title product;

1. filtrationThe mixture was filtered
2. filtrationthrough filter paper
3. washthe filtrate was washed with sat. NaHCO3 (300 ml), 2 M Na2SO3 (300 ml) and sat. brine (300 ml)
4. dry with materialThe solution was dried over MgSO4
5. filtrationfiltered
6. washwashing MgSO4 bed with DCM (100 ml)
7. customThe solvent was removed in vacuo
8. dissolutionThe crude product was dissolved in diethyl ether (300 ml)
9. customto stand at RT
10. customThe resulting crystalline solid was isolated
11. customby decanting off the mother liquors
12. washThe crystals were washed with diethyl ether

ORD-Eintrag

ord-429f4552b0764d83995f58ff50fdfc3c

Quelldatensatz

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08754085B2