Citric Acid → 3-Amino-6-iodopyrazine-2-carboxylic acid

HRID 272054

Reaction equation

HRID 272054 reaction equation
C[O:2][C:3]([C:5]1[C:10]([NH2:11])=[N:9][CH:8]=[C:7]([I:12])[N:6]=1)=[O:4].[OH-].[Li+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1COCC1.O.ClCCl>[NH2:11][C:10]1[C:5]([C:3]([OH:4])=[O:2])=[N:6][C:7]([I:12])=[CH:8][N:9]=1

Participants

7

Reactant 3

HCID 311Citric AcidHCID 3939Lithium HydroxideHCID 11087124Methyl 3-amino-6-iodopyrazine-2-carboxylate

Product 1

HCID 468356023-Amino-6-iodopyrazine-2-carboxylic acidYield 87%

Reagents, catalysts & solvents 3

HCID 962WaterSolvent3×HCID 6344DichloromethaneSolventHCID 8028TetrahydrofuranSolvent

Procedure

3-amino-6-iodo-pyrazine-2-carboxylic acid methyl ester (45 g, 161 mmol) was dissolved in 750 ml of THF. 90 ml of water and 40 ml of a 4 M solution of lithium hydroxide in water was added. The mixture was stirred at room temperature for 2 hours or until TLC analysis showed only baseline material. A solution of 10% citric acid in water was added to adjust the pH to about 3-4. The mixture was diluted with dichloromethane and the organic phase was separated. The aqueous layer was extracted three times with dichloromethane and the combined organic phases were dried over sodium sulfate and evaporated. The residue was dried in vacuo to afford 37.0 g (140 mmol; 87% yield) of 3-amino-6-iodo-pyrazine-2-carboxylic acid as a yellow powder. 1H-NMR (d6-DMSO) δ: 11.70 s, weak, 8.44 [1H] s, 7.50 [2H] s,br. MS: m/z 266 [MH+].

Workup

  1. customthe organic phase was separated
  2. extractionThe aqueous layer was extracted three times with dichloromethane
  3. dry with materialthe combined organic phases were dried over sodium sulfate
  4. customevaporated
  5. customThe residue was dried in vacuo

Sources & evidence

ORD record
ord-00d22c46ed3a4150b803937a033a24f9
Source dataset
uspto-grants-2008_11
Patent number
US07452993B2

Linked notes

Loading…