Benzoyl Peroxide → Ethyl 5-(bromomethyl)pyrazine-2-carboxylate

HRID 458430Notes

Reaction equation

HRID 458430 reaction equation
[CH3:1][C:2]1[N:3]=[CH:4][C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[N:6][CH:7]=1.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1.[Br:31]N1C(=O)CCC1=O>C(Cl)(Cl)(Cl)Cl.[W]>[Br:31][CH2:1][C:2]1[N:3]=[CH:4][C:5]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[N:6][CH:7]=1

Participants

6

Reactant 3

HCID 7187Benzoyl PeroxideHCID 67184N-bromobutanimideHCID 16114819Ethyl 5-methylpyrazine-2-carboxylate

Product 1

HCID 22050280Ethyl 5-(bromomethyl)pyrazine-2-carboxylateYield 45%

Reagents, catalysts & solvents 2

HCID 23964TungstenCatalystHCID 5943Carbon TetrachlorideSolvent

Procedure

Ethyl 5-methyl-2-pyrazinecarboxylate (10.0 g, 60.18 mmol), benzoyl peroxide (1.46 g, 6.02 mmol) and N-bromo succinimide (11.78 g, 66.19 mmol) in 80 mL CCl4 was heated to reflux while a 75 W tungsten lamp was shining on the reaction mixture. After 4 h the reaction mixture was cooled and the precipitate filtered off. The red filtrate was concentrated and the residue redissolved in EtOAc and washed with sat'd NaHCO3, 5% Na2S2O3, brine and the organics dried (Na2SO4), filtered and concentrated. Chromatography on silica gel using 1:1 Hexanes:EtOAc eluted the product. After concentration the title compound (6.64 g, 27.08 mmol, 45% yield) was isolated as a yellow oil: 1H NMR (CDCl3, 400 MHz) δ 9.22 (s, 1H), 8.80 (s, 1H), 4.58 (s, 2H), 4.49 (dd, J=14.3, 7.1 Hz, 2H), 1.43 (t, J=7.2 Hz, 3H).

Workup

  1. temperatureAfter 4 h the reaction mixture was cooled
  2. filtrationthe precipitate filtered off
  3. concentrationThe red filtrate was concentrated
  4. dissolutionthe residue redissolved in EtOAc
  5. washwashed with sat'd NaHCO3, 5% Na2S2O3, brine
  6. dry with materialthe organics dried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated
  9. washChromatography on silica gel using 1:1 Hexanes:EtOAc eluted the product

Sources & evidence

ORD record
ord-74730626cfe94ac78ddb74e3a4f612bb
Source dataset
uspto-grants-2007_03
Patent number
US07189851B2

Reaction notes

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