Hydrogen Bromide → 7-Methoxy-1,5-naphthyridin-2(1H)-one

HRID 656877Notes

Reaction equation

HRID 656877 reaction equation
C[O:2][C:3]1[CH:12]=[CH:11][C:10]2[C:5](=[CH:6][C:7]([O:13][CH3:14])=[CH:8][N:9]=2)[N:4]=1.Br>C(O)(=O)C>[CH3:14][O:13][C:7]1[CH:6]=[C:5]2[C:10]([CH:11]=[CH:12][C:3](=[O:2])[NH:4]2)=[N:9][CH:8]=1

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 585794032,7-Dimethoxy-1,5-naphthyridine

Product 1

HCID 578154107-Methoxy-1,5-naphthyridin-2(1H)-oneYield 86.3%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

2,7-bis(methoxy)-1,5-naphthyridine (7.45 g, 39.210 mmol) stirred in glacial acetic acid (100 ml) at rt under argon, was treated with 33% HBr in acetic acid (100 ml). After stirring at rt for 18 h, the solvents were evaporated under reduced pressure (copious fumes of HBr were produced). The orange solid residue was stirred with water (ca. 250 ml) and the pH of the suspension was adjusted to ca. pH 6 by addition of solid sodium hydrogen carbonate. The mixture was then filtered and dried in a vacuum desiccator over P2O5 overnight to give 7-(methoxy)-1,5-naphthyridin-2(1H)-one as an off-white solid (5.958 g, 86%).

Workup

  1. customthe solvents were evaporated under reduced pressure (copious fumes of HBr were produced)
  2. stirringThe orange solid residue was stirred with water (ca. 250 ml)
  3. additionthe pH of the suspension was adjusted to ca. pH 6 by addition of solid sodium hydrogen carbonate
  4. filtrationThe mixture was then filtered
  5. dry with materialdried in a vacuum desiccator over P2O5 overnight

Sources & evidence

ORD record
ord-04aac906bc0b4336a6d5d2277b042908
Source dataset
uspto-grants-2011_12
Patent number
US08071592B2

Reaction notes

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