Sodium Thiosulfate → Methyl 3-amino-6-iodopyrazine-2-carboxylate

HRID 272053

Reaction equation

HRID 272053 reaction equation
[NH2:1][C:2]1[C:3]([C:8]([O:10][CH3:11])=[O:9])=[N:4][CH:5]=[CH:6][N:7]=1.[I:12]N1C(=O)CCC1=O.S([O-])([O-])(=O)=S.[Na+].[Na+]>CN(C=O)C>[CH3:11][O:10][C:8]([C:3]1[C:2]([NH2:1])=[N:7][CH:6]=[C:5]([I:12])[N:4]=1)=[O:9]

Participants

5

Reactant 3

HCID 24477Sodium ThiosulfateHCID 72669Methyl 3-aminopyrazinecarboxylateHCID 120273N-Iodosuccinimide

Product 1

HCID 11087124Methyl 3-amino-6-iodopyrazine-2-carboxylateYield 61.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
70 °C

Procedure

Methyl 3-amino-2-pyrazinecarboxylate (10 g, 65.3 mmol) and N-iodosuccinimide (24 g, 106.7 mmol) were dissolved in anhydrous DMF (150 mL) and the mixture was stirred at 70° C. for 15 hours under a nitrogen atmosphere. The mixture was then cooled to room temperature and a saturated aqueous solution of sodium thiosulfate (400 mL) was added. The suspension was sonicated for 15 minutes, concentrated under vacuum and dispersed in water. The crude product was filtered off and washed with cold ethanol. The residue was crystallized from ethanol, using decolorizing charcoal to afford 3-amino-6-iodo-pyrazine-2-carboxylic acid methyl ester (11.2 g, 61% yield) as orange needles. 1H-NMR (d6-DMSO) δ: 8.57 [1H] s, 7.59 [2H] s,br, 3.93 [3H] s. MS: m/z 280 [MH+].

Workup

  1. temperatureThe mixture was then cooled to room temperature
  2. customThe suspension was sonicated for 15 minutes
  3. concentrationconcentrated under vacuum
  4. additiondispersed in water
  5. filtrationThe crude product was filtered off
  6. washwashed with cold ethanol
  7. customThe residue was crystallized from ethanol

Sources & evidence

ORD record
ord-57810c7f678345f98e9ba23883ec6ff3
Source dataset
uspto-grants-2008_11
Patent number
US07452993B2

Linked notes

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