Sodium Sulfite → 5-Bromo-2,3-dimethoxypyrazine

HRID 1085812Notes

Reaction equation

HRID 1085812 reaction equation
[Br:1]NC(=O)CCC(N)=O.[CH3:10][O:11][C:12]1[C:17]([O:18][CH3:19])=[N:16][CH:15]=[CH:14][N:13]=1.[O-]S([O-])=O.[Na+].[Na+]>CN(C=O)C>[Br:1][C:14]1[CH:15]=[N:16][C:17]([O:18][CH3:19])=[C:12]([O:11][CH3:10])[N:13]=1

Participants

5

Reactant 3

HCID 24437Sodium SulfiteHCID 9834204N-BromosuccinamideHCID 124023092,3-Dimethoxypyrazine

Product 1

HCID 151144395-Bromo-2,3-dimethoxypyrazine

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Conditions

Temperature
25 °C

Procedure

A solution of 14.6 gm of N-bromosuccinamide, 32 ml of dry DMF was added to a stirred solution of 11 gm (0.078 mol) of 2,3 dimethoxypyrazine in 14 ml of DMF at 0° C. whereupon the reaction was warmed to 25° C. and stirred for 16 hours. The reaction mixture was then cooled in an ice bath and to it was added aqueous Na2SO3 to remove the bromine and this was poured into ice water. The resulting crystalline solid was filtered, triturated with water and dried to give the title compound. NMR (CDCl3) δ 4.0, 4.02(2s, 6H, --OCH3), 7.70(s,lH).

Workup

  1. temperatureThe reaction mixture was then cooled in an ice bath and to it
  2. customto remove the bromine
  3. additionthis was poured into ice water
  4. filtrationThe resulting crystalline solid was filtered
  5. customtriturated with water
  6. customdried

Sources & evidence

ORD record
ord-a6c6175a7b81473bafd3cd3491299cb1
Source dataset
uspto-grants-1991_04
Patent number
US05011847

Reaction notes

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