Hydrochloric Acid → 5-chloro-3,4-dihydroquinolin-2(1H)-one

HRID 1649417Notes

Reaction equation

HRID 1649417 reaction equation
N[C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH2:4][CH2:5][C:6](=[O:12])[NH:7]2.O.N([O-])=O.[Na+].[ClH:18]>>[Cl:18][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH2:4][CH2:5][C:6](=[O:12])[NH:7]2

Participants

5

Reactant 4

HCID 313Hydrochloric Acid2×HCID 962WaterHCID 115065075-Amino-3,4-dihydroquinolin-2(1H)-oneHCID 23668193Sodium Nitrite

Product 1

HCID 190277365-chloro-3,4-dihydroquinolin-2(1H)-one

Procedure

45 g of 5-amino-3,4-dihydrocarbostyril was suspended in 250 ml of a 15% hydrochloric acid and 250 ml of water having dissolved therein 20 g of sodium nitrite was added dropwise to the mixture followed by stirring at room temperature for 1 hour. The resulting solution was added dropwise to a solution prepared by dissolving 41.2 g of cuprous chloride in 120 ml of concentrated hydrochloric acid at room temperature while stirring. After completion of the addition, the mixture was heated on a water bath at 50° to 60° C. for 1 hour while stirring. After allowing the mixture to cool to precipitate crystals, they were collected by filtration and washed with water. The wet crystals were dissolved in chloroform and insoluble materials were removed by filtration. The residue was dried over anhydrous sodium sulfate. After removal of the solvent the residue was dissolved with heating and the solution was treated with activated carbon while hot. The ethanolic solution thus-treated was concentrated under reduced pressure. Recrystallization of the concentrate from ethanol gave 31.5 g of 5-chloro-3,4-dihydrocarbostyril having a melting point of 193° to 194° C.

Workup

  1. dissolutiondissolved
  2. additionThe resulting solution was added dropwise to a solution
  3. customprepared
  4. stirringwhile stirring
  5. additionAfter completion of the addition
  6. temperaturethe mixture was heated on a water bath at 50° to 60° C. for 1 hour
  7. stirringwhile stirring
  8. temperatureto cool
  9. customto precipitate crystals, they
  10. filtrationwere collected by filtration
  11. washwashed with water
  12. dissolutionThe wet crystals were dissolved in chloroform
  13. custominsoluble materials were removed by filtration
  14. dry with materialThe residue was dried over anhydrous sodium sulfate
  15. customAfter removal of the solvent the residue
  16. dissolutionwas dissolved
  17. temperaturewith heating
  18. additionthe solution was treated with activated carbon while hot
  19. additionThe ethanolic solution thus-treated
  20. concentrationwas concentrated under reduced pressure
  21. customRecrystallization of the
  22. concentrationconcentrate from ethanol

Sources & evidence

ORD record
ord-fe937c256a744a148e2508bb3facd206
Source dataset
uspto-grants-1983_11
Patent number
US04416884

Reaction notes

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