Cesium carbonate → 4-(2-Methoxy-4-nitrophenyl)-6-methylpyridazine 1-oxide

HRID 1803146Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:8]=[C:7]([N+:9]([O-:11])=[O:10])[CH:6]=[CH:5][C:4]=1B1OC(C)(C)C(C)(C)O1.Br[C:22]1[CH:27]=[C:26]([CH3:28])[N+:25]([O-:29])=[N:24][CH:23]=1.C(=O)([O-])[O-].[Cs+].[Cs+]>Cl[Pd]Cl.C1(P(C2C=CC=CC=2)[C-]2C=CC=C2)C=CC=CC=1.[C-]1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=C1.[Fe+2].O1CCOCC1>[CH3:1][O:2][C:3]1[CH:8]=[C:7]([N+:9]([O-:11])=[O:10])[CH:6]=[CH:5][C:4]=1[C:22]1[CH:27]=[C:26]([CH3:28])[N+:25]([O-:29])=[N:24][CH:23]=1

Participants

Conditions

Temperature: 110 °C

Procedure

Step L (2): A high pressure bottle was charged with 2-(2-methoxy-4-nitrophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (6.1 g, 13.8 mmol), [1,1′-bis(diphenylphosphino)ferrocene]-dichloropalladium(II) (1:1 complex with dichloromethane, 1.0 g, 1.1 mmol), 4-bromo-6-methylpyridazine 1-oxide (2.0 g, 11 mmol, B. Buettelmann et. al US Patent Application Publication 2004/0254179 A1), cesium carbonate (in 5 mL of water, 8.0 g, 21 mmol), and 1,4-dioxane (80 mL). The mixture was degassed by bubbling nitrogen through the solution. The bottle was capped and heated at 110° C. for 2 h. The resulting mixture was filtered through diatomaceous earth (Celite®). The filtrated was concentrated in vacuo. The crude product was purified using silica gel column chromatography (EtOAc/hexane) to afford 4-(2-methoxy-4-nitrophenyl)-6-methylpyridazine 1-oxide (1.4 g, 49% yield).

Workup

customThe mixture was degassed
customby bubbling nitrogen through the solution
customThe bottle was capped
filtrationThe resulting mixture was filtered through diatomaceous earth (Celite®)
concentrationThe filtrated was concentrated in vacuo
customThe crude product was purified

Sources & evidence

ORD record: ord-05b6f1e61ca24457a2a6a5a2d28da253
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08349880B2

Reaction notes

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