Cesium carbonate → Ethyl 5-chloro-2-pyrazin-2-ylbenzoate

HRID 1948564Notes

Reaction equation

HRID 1948564 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5](B(O)O)=[C:4]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:3]=1.I[C:17]1[CH:22]=[N:21][CH:20]=[CH:19][N:18]=1.C([O-])([O-])=O.[Cs+].[Cs+]>CN(C=O)C.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2]>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:17]2[CH:22]=[N:21][CH:20]=[CH:19][N:18]=2)=[C:4]([CH:3]=1)[C:11]([O:13][CH2:14][CH3:15])=[O:12]

Participants

6

Reactant 3

HCID 10796Cesium carbonateHCID 642841IodopyrazineHCID 230053604-Chloro-2-(ethoxycarbonyl)benzeneboronic acid

Product 1

HCID 58408404Ethyl 5-chloro-2-pyrazin-2-ylbenzoate

Reagents, catalysts & solvents 2

HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 6228DimethylformamideSolvent

Procedure

A mixture of [4-chloro-2-(ethoxycarbonyl)phenyl]boronic acid (3-1, 0.300 g, 1.313 mmol, 1.0 equiv), 2-iodopyrazine (0.352 g, 1.707 mmol, 1.3 equiv), 4M Cs2CO3 (1.15 mL, 4.60 mmol, 3.5 equiv) and PdCl2(dppf) (0.096 g, 0.131 mmol, 0.1 equiv) in DMF (6.5 mL) was combined and stirred at room temperature overnight. The reaction was partitioned between EtOAc and saturated aqueous NaHCO3, washed with water, brine, dried over MgSO4, and concentrated by rotary evaporation. The residue was purified by column chromatography on silica gel (EtOAc/hexanes) to provide 3-2 as a solid. ESI+ MS [M+H]+ C18H17N3O2: 263.01 found, 263.70 required.

Workup

  1. customThe reaction was partitioned between EtOAc and saturated aqueous NaHCO3
  2. washwashed with water, brine
  3. dry with materialdried over MgSO4
  4. concentrationconcentrated by rotary evaporation
  5. customThe residue was purified by column chromatography on silica gel (EtOAc/hexanes)

Sources & evidence

ORD record
ord-f9dbe78faf5b4eeb9d7b91e27f21b481
Source dataset
uspto-grants-2013_03
Patent number
US08399494B2

Reaction notes

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