Hydrochloric Acid → 5-chloro-1-(4-fluorophenyl)-3-methoxypyrazin-2(1H)-one

HRID 1676397Notes

Reaction equation

HRID 1676397 reaction equation
Cl[C:2]1[C:3](=[O:16])[N:4]([C:9]2[CH:14]=[CH:13][C:12]([F:15])=[CH:11][CH:10]=2)[CH:5]=[C:6]([Cl:8])[N:7]=1.[CH3:17][O-:18].[Na+].Cl>CO>[Cl:8][C:6]1[N:7]=[C:2]([O:18][CH3:17])[C:3](=[O:16])[N:4]([C:9]2[CH:14]=[CH:13][C:12]([F:15])=[CH:11][CH:10]=2)[CH:5]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 10942334Sodium MethoxideHCID 672211573,5-dichloro-1-(4-fluorophenyl)pyrazin-2(1H)-one

Product 1

HCID 673472395-chloro-1-(4-fluorophenyl)-3-methoxypyrazin-2(1H)-oneYield 100%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

3,5-dichloro-1-(4-fluorophenyl)pyrazin-2(1H)-one (13.0 g, 50.2 mmol; prepared according to the general methods described by M. Tutonda, et al., Tetrahedron, 1990, 46, 5715) dissolved in absolute methanol (100 mL) was treated with NaOMe (6.78 g, 125 mmol). The reaction mixture was stirred at room temp for 1 hour, neutralized with 2N HCl (Et2O solution), and evaporated the solvent under reduced pressure. The residue was treated with EtOAc, washed with 0.5N HCl solution, dried over MgSO4, and concentrated under reduced pressure to give the desired product (12.8 g, 100%). LRMS (ESI pos) m/e 254.9, 256.9 (M+1, Cl pattern). 1H-NMR (400 MHz, CDCl3) δ 7.39 (m, 2H), 7.20 (t, 2H), 6.95 (s, 1H), 4.05 (s, 3H); 19F-NMR (376 MHz, CDCl3) δ −111.5.

Workup

  1. customprepared
  2. customevaporated the solvent under reduced pressure
  3. additionThe residue was treated with EtOAc
  4. washwashed with 0.5N HCl solution
  5. dry with materialdried over MgSO4
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-6fb8610eba254195abf7b65fafb0b57f
Source dataset
uspto-grants-2011_08
Patent number
US08003662B2

Reaction notes

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