Phosphorus tribromide → 2-Bromo-6-chloro-1,7-naphthyridine

HRID 1502407Notes

Reaction equation

HRID 1502407 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][N:11]=1)[NH:8][C:7](=O)[CH:6]=[CH:5]2.P(Br)(Br)[Br:14]>C(=O)([O-])[O-].[Na+].[Na+]>[Br:14][C:7]1[CH:6]=[CH:5][C:4]2[C:9](=[CH:10][N:11]=[C:2]([Cl:1])[CH:3]=2)[N:8]=1

Participants

4

Reactant 2

HCID 24614Phosphorus tribromideHCID 155923736-Chloro-1,7-naphthyridin-2(1H)-one

Product 1

HCID 772312742-Bromo-6-chloro-1,7-naphthyridineYield 50%

Reagents, catalysts & solvents 1

HCID 10340Sodium CarbonateSolvent

Conditions

Temperature
130 °C

Procedure

A mixture of 6-chloro-1,7-naphthyridin-2(1H)-one (1.0 g, 5.5 mmol) and phosphorus tribromide (10 mL) was heated in a sealed tube at 130° C. for 20 hours. The cooled reaction mixture was poured onto ice, diluted with saturated aqueous sodium carbonate solution (100 mL), and extracted with ethyl acetate (2×200 mL). The combined organic layers were dried over sodium sulfate, filtered, and evaporated in vacuo to afford a residue that was purified by flash chromatography (silica, 40 g, ISCO, 0-80% ethyl acetate in heptane) to afford the title compound as a white solid (700 mg, 50%). 1H NMR (400 MHz, DMSO) δ 9.24 (s, 1H), 8.38 (d, J=8.7 Hz, 1H), 8.20 (s, 1H), 8.02 (d, J=8.7 Hz, 1H).

Workup

  1. customThe cooled reaction mixture
  2. additionwas poured onto ice
  3. extractionextracted with ethyl acetate (2×200 mL)
  4. dry with materialThe combined organic layers were dried over sodium sulfate
  5. filtrationfiltered
  6. customevaporated in vacuo
  7. customto afford a residue that
  8. customwas purified by flash chromatography (silica, 40 g, ISCO, 0-80% ethyl acetate in heptane)

Sources & evidence

ORD record
ord-aa6bd069208c4a10a0ddd403dd21e9c3
Source dataset
uspto-grants-2015_12
Patent number
US09206175B2

Reaction notes

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