Potassium Carbonate → 2-(3,4,5-trimethoxy-phenyl)-5H-pyrrolo[2,3-b]pyrazine

HRID 1677379Notes

Reaction equation

Br[C:2]1[N:3]=[C:4]2[CH:10]=[CH:9][NH:8][C:5]2=[N:6][CH:7]=1.[CH3:11][O:12][C:13]1[CH:14]=[C:15](B(O)O)[CH:16]=[C:17]([O:21][CH3:22])[C:18]=1[O:19][CH3:20].C([O-])([O-])=O.[K+].[K+].O1CCOCC1>O>[CH3:22][O:21][C:17]1[CH:16]=[C:15]([C:2]2[N:3]=[C:4]3[CH:10]=[CH:9][NH:8][C:5]3=[N:6][CH:7]=2)[CH:14]=[C:13]([O:12][CH3:11])[C:18]=1[O:19][CH3:20]

Participants

Conditions

Temperature: 110 °C

Procedure

A flask was charged with 2-bromo-5H-pyrrolo[2,3-b]pyrazine (9.5 g, 48 mmol), 3,4,5-trimethoxyphenylboronic acid (13.22, 62 mmol), and K2CO3 (19.9, 144 mmol). Dioxane (213 ml) and water (71 ml) were added, and the solution was vacuum degassed under argon. [1,1′-bis(Diphenylphosphino)ferrocene]dichloro-palladium(ll) (3.92 g, 4.8 mmol) was added, and the reaction mixture was refluxed (110° C.) overnight. The reaction mixture was filtered through a plug of celite using dichloromethane, and the filtrate was concentrated giving a black oil. The oil was purified by silica gel chromatography using 5%-60% EtOAc in hexanes as eluant to provide 12.12 g (89%) of 2-(3,4,5-trimethoxy-phenyl)-5H-pyrrolo[2,3-b]pyrazine.

Workup

customdegassed under argon
filtrationThe reaction mixture was filtered through a plug of celite
concentrationthe filtrate was concentrated
customgiving a black oil
customThe oil was purified by silica gel chromatography

Sources & evidence

ORD record: ord-0c4f7b652f264d0f9abc077187cf815b
Source dataset: uspto-grants-2011_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08008298B2

Reaction notes

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