Ammonia → 4-Bromo-1,8-naphthyridine

HRID 1253519Notes

Reaction equation

HRID 1253519 reaction equation
[N:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][N:9]=2)[C:4](O)=[CH:3][CH:2]=1.[Br-:12].[Br-].[Br-].[P+3]=O.N>C(#N)C>[Br:12][C:4]1[C:5]2[C:10](=[N:9][CH:8]=[CH:7][CH:6]=2)[N:1]=[CH:2][CH:3]=1

Participants

5

Reactant 3

HCID 222AmmoniaHCID 178516463HCID 178516463, compoundHCID 178527000HCID 178527000, compound

Product 1

HCID 124225274-Bromo-1,8-naphthyridine

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a solution of 1,8-naphthyridin-4-ol (59 g, 400 mmol) in acetonitrile (500 ml) was added phosphorus oxide tribromide. The reaction mixture was heated to reflux. After 1 hour, the reaction mixture was carefully diluted with ice and the resulting solution was basified with ammonia solution (25%) to pH>7. The reaction mixture was partially concentrated in vacuo, then extracted with chloroform (4×500 ml). The organics were dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (ethyl acetate/petroleum ether gradient) to afford 4-bromo-1,8-naphthyridine.

Workup

  1. temperatureThe reaction mixture was heated to reflux
  2. additionthe reaction mixture was carefully diluted with ice
  3. concentrationThe reaction mixture was partially concentrated in vacuo
  4. extractionextracted with chloroform (4×500 ml)
  5. dry with materialThe organics were dried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified by column chromatography on silica gel (ethyl acetate/petroleum ether gradient)

Sources & evidence

ORD record
ord-99afe22952044c07a956f231f5c1e3c1
Source dataset
uspto-grants-2013_06
Patent number
US08455477B2

Reaction notes

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