Methyl 5-chloropyrazine-2-carboxylate → 5-Chloropyrazinoic acid

HRID 641158Notes

Reaction equation

HRID 641158 reaction equation
[Cl:1][C:2]1[N:3]=[CH:4][C:5]([C:8]([O:10]C)=[O:9])=[N:6][CH:7]=1.[Cl-].[Li+]>CN(C=O)C>[Cl:1][C:2]1[N:3]=[CH:4][C:5]([C:8]([OH:10])=[O:9])=[N:6][CH:7]=1

Participants

4

Reactant 2

HCID 406081Methyl 5-chloropyrazine-2-carboxylateHCID 433294Lithium Chloride

Product 1

HCID 4654725-Chloropyrazinoic acid

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
140 °C

Procedure

Methyl 5-chloropyrazine-2-carboxylate (CAS no. 33332-25-1)(345.1 g) was dissolved in DMF (1.73 l). Lithium chloride (423.9 g) was added and the mixture heated to 140° C. over one hour. The mixture was evaporated, and the residue dissolved in water (3.4 l) by continued stirring. The solution was acidified by addition of 2N HCl (900 ml) and extracted into ethyl acetate (5×1.73 l). The combined organic extracts were washed with water (2×900 ml), brine (900 ml), dried (MgSO4), and evaporated to give the title compound (298.1 g). 1H NMR δ (400.132 MHz, DMSO) 8.92 (d, 1H), 9.02 (d, 1H), 13.87 (s, 1H).

Workup

  1. customThe mixture was evaporated
  2. dissolutionthe residue dissolved in water (3.4 l)
  3. additionThe solution was acidified by addition of 2N HCl (900 ml)
  4. extractionextracted into ethyl acetate (5×1.73 l)
  5. washThe combined organic extracts were washed with water (2×900 ml), brine (900 ml)
  6. dry with materialdried (MgSO4)
  7. customevaporated

Sources & evidence

ORD record
ord-76e3248ccf6c4443a331568e0068310f
Source dataset
uspto-grants-2010_04
Patent number
US07696191B2

Reaction notes

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