Phosphorus oxychloride → 4,8-dichloro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-one

HRID 1398396Notes

Reaction equation

HRID 1398396 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[C:14]3[C:9](=[CH:10][N+:11]([O-])=[CH:12][CH:13]=3)[C:8](=[O:16])[N:7]([CH3:17])[C:6]=2[CH:18]=1.O=P(Cl)(Cl)[Cl:21]>>[Cl:21][C:10]1[N:11]=[CH:12][CH:13]=[C:14]2[C:9]=1[C:8](=[O:16])[N:7]([CH3:17])[C:6]1[CH:18]=[C:2]([Cl:1])[CH:3]=[CH:4][C:5]2=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 867103838-Chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine 3-oxide

Product 1

HCID 867103844,8-dichloro-6-methylbenzo[c][2,7]naphthyridin-5(6H)-oneYield 56%

Procedure

A stirred solution of 8-chloro-6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine 3-oxide (0.5 g, 1.918 mmol) in POCl3 (3.58 mL, 38.4 mmol) was heated to reflux for 6 h. The reaction mixture was concentrated under reduced pressure. The residue was then partitioned between dichloromethane (100 mL) and saturated sodium bicarbonate solution (200 mL). The organic layer was separated and washed again with brine solution (50 mL), dried over sodium sulphate, and concentrated to afford 4,8-dichloro-6 methylbenzo[c][2,7]naphthyridin-5(6H)-one (0.3 g, 1.075 mmol, 56% crude yield). The material was carried on without further purification. LC/MS (ESI) m/e 280.8, [(M+2H)+, calcd for C13H9Cl2N2O, 280.8]; LC/MS retention time (method C): tR=2.06 min.

Workup

  1. temperatureto reflux for 6 h
  2. concentrationThe reaction mixture was concentrated under reduced pressure
  3. customThe residue was then partitioned between dichloromethane (100 mL) and saturated sodium bicarbonate solution (200 mL)
  4. customThe organic layer was separated
  5. washwashed again with brine solution (50 mL)
  6. dry with materialdried over sodium sulphate
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-b13b7c0e7d734513afc4dc0ceb1250f3
Source dataset
uspto-grants-2014_12
Patent number
US08901305B2

Reaction notes

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