2-Amino-3,5-dibromopyrazine → 5-Bromo-3-ethoxypyrazin-2-amine

HRID 2287382Notes

Reaction equation

HRID 2287382 reaction equation
[NH2:1][C:2]1[C:7](Br)=[N:6][C:5]([Br:9])=[CH:4][N:3]=1.[O-:10][CH2:11][CH3:12].[Na+]>C(O)C>[NH2:1][C:2]1[C:7]([O:10][CH2:11][CH3:12])=[N:6][C:5]([Br:9])=[CH:4][N:3]=1

Participants

4

Reactant 2

HCID 6200042-Amino-3,5-dibromopyrazineHCID 2723922Sodium ethoxide

Product 1

HCID 126746115-Bromo-3-ethoxypyrazin-2-amineYield 87.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 2-amino-3,5-dibromopyrazine (obtained as described in Gazz. Chim. Ital., 1960, 90, 1807) (1.26 g) and sodium ethoxide (0.4 g) in ethanol (50 ml) was heated under reflux for 4 hours. Volatile material was removed by evaporation and the residue was partitioned between water (20 ml) and ethyl acetate (50 ml). The organic layer was separated and dried (MgSO4). Volatile material was removed by evaporation to give 2-amino-5-bromo-3-ethoxypyrazine (0.95 g); 1H NMR (d6 -DMSO): 1.4 (t, 3H), 4.3 (q, 2H), 6.4 (br s, 2H), 7.6 (s, 2H); mass spectrum (+ve CI): 218 (M+H)+.

Workup

  1. temperatureunder reflux for 4 hours
  2. customVolatile material was removed by evaporation
  3. customthe residue was partitioned between water (20 ml) and ethyl acetate (50 ml)
  4. customThe organic layer was separated
  5. dry with materialdried (MgSO4)
  6. customVolatile material was removed by evaporation

Sources & evidence

ORD record
ord-23898cfb5cf44b29b059f88078812387
Source dataset
uspto-grants-2000_07
Patent number
US06083951

Reaction notes

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