Phosphorus oxychloride → 4-chloro-5,7-diethyl-1,6-naphthyridin-2(1H)-one

HRID 1587504Notes

Reaction equation

HRID 1587504 reaction equation
[CH2:1]([C:3]1[N:12]=[C:11]([CH2:13][CH3:14])[CH:10]=[C:9]2[C:4]=1[C:5](O)=[CH:6][C:7](=[O:15])[NH:8]2)[CH3:2].P(Cl)(Cl)([Cl:19])=O>>[Cl:19][C:5]1[C:4]2[C:9](=[CH:10][C:11]([CH2:13][CH3:14])=[N:12][C:3]=2[CH2:1][CH3:2])[NH:8][C:7](=[O:15])[CH:6]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychloride2×HCID 546846815,7-diethyl-4-hydroxy-1,6-naphthyridin-2(1H)-one

Product 1

HCID 190937334-chloro-5,7-diethyl-1,6-naphthyridin-2(1H)-one

Procedure

Compound C (17.6 g) was dissolved in phosphorus oxychloride (100 ml) and the mixture was heated at reflux for 24 hours. Unreacted phosphorus oxychloride was removed by evaporation and the residue was dissolved in concentrated hydrochloric acid (100 ml) containing water (15 ml). The mixture was heated at reflux for 4 hour. The mixture was then diluted with water (500 ml) and basified with solid potassium carbonate. The resulting precipitate was collected by filtration and washed with water. The solid was purified by flash chromatography, eluting with ethyl acetate, to give 4-chloro-5,7-diethyl-1,6-naphthyridin-2(1H)-one (D) (8.9 g); m.p. 172°-174° C.; NMR (CDCl3): 1.35(dt, 6H), 2.86(q, 2H), 3.49(q, 2H), 6.83(s, 1H), 7.0(s, 1H), 12.4(broad, 1H); mass spectrum (CI, ammonia): 237 (M+H)+ ; microanalysis, found: C, 60.3; H, 5.5; N, 11.5%; C12H13ClN2O requires: C, 60.9; H, 5.5; N, 11.8%.

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux for 24 hours
  3. customwas removed by evaporation
  4. dissolutionthe residue was dissolved in concentrated hydrochloric acid (100 ml)
  5. additioncontaining water (15 ml)
  6. temperatureThe mixture was heated
  7. temperatureat reflux for 4 hour
  8. additionThe mixture was then diluted with water (500 ml)
  9. filtrationThe resulting precipitate was collected by filtration
  10. washwashed with water
  11. customThe solid was purified by flash chromatography
  12. washeluting with ethyl acetate

Sources & evidence

ORD record
ord-5f9dc93d187146aeba826d41f4cafe26
Source dataset
uspto-grants-1993_06
Patent number
US05217976

Reaction notes

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