Phosphorus oxychloride → 2-Chloro-7,8-dihydro-1,6-naphthyridin-5(6H)-one

HRID 533142Notes

Reaction equation

HRID 533142 reaction equation
O[C:2]1[CH:11]=[CH:10][C:9]2[C:8](=[O:12])[NH:7][CH2:6][CH2:5][C:4]=2[N:3]=1.P(Cl)(Cl)([Cl:15])=O>>[Cl:15][C:2]1[CH:11]=[CH:10][C:9]2[C:8](=[O:12])[NH:7][CH2:6][CH2:5][C:4]=2[N:3]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178517695HCID 178517695, compound

Product 1

HCID 722129652-Chloro-7,8-dihydro-1,6-naphthyridin-5(6H)-oneYield 36%

Conditions

Temperature
100 °C

Procedure

A mixture of 2-hydroxy-7,8-dihydro-6H-[1,6]naphthyridin-5-one (17 g, 73.1 mmol) in phosphorus oxychloride (30 mL) was stirred at 100° C. for 8 h. The solvent was evaporated in vacuo. The mixture was basified with a saturated solution of NaHCO3 and extracted with EtOAc. The organic layer was separated, dried (Na2SO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica; petroleum ether/EtOAc 1/1). The desired fractions were collected and the solvents evaporated in vacuo to yield 2-chloro-7,8-dihydro-1,6-naphthyridin-5(6H)-one (4.81 g, 36%) as a solid.

Workup

  1. customThe solvent was evaporated in vacuo
  2. extractionextracted with EtOAc
  3. customThe organic layer was separated
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. customthe solvents evaporated in vacuo
  7. customThe crude product was purified by flash column chromatography (silica; petroleum ether/EtOAc 1/1)
  8. customThe desired fractions were collected
  9. customthe solvents evaporated in vacuo

Sources & evidence

ORD record
ord-9134168d987344d5a29709d46063e61d
Source dataset
uspto-grants-2014_10
Patent number
US08853237B2

Reaction notes

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