Potassium Hydroxide → 9-chloro-6-imino-4-oxo-3-phenyl-6H-pyrido[2,1-a]isoindole-1-carboxylic acid

HRID 1885348Notes

Reaction equation

HRID 1885348 reaction equation
[Cl:1][C:2]1[CH:11]=[C:10]2[C:5]([CH:6]=[N:7][N:8]3[C:15](=[O:16])[C:14]([C:17]4[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=4)=[CH:13][C:12]([C:23]([OH:25])=[O:24])=[C:9]32)=[CH:4][CH:3]=1.[OH-].[K+]>CO>[Cl:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[NH:7])[N:8]3[C:15](=[O:16])[C:14]([C:17]4[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=4)=[CH:13][C:12]([C:23]([OH:25])=[O:24])=[C:9]32)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 1895709410-chloro-4-oxo-3-phenyl-4H-pyrido[2,1-a]phthalazine-1-carboxylic acid

Product 1

HCID 189570979-chloro-6-imino-4-oxo-3-phenyl-6H-pyrido[2,1-a]isoindole-1-carboxylic acidYield 94.9%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

3.5 g of 10-chloro-4-oxo-3-phenyl-4H-pyrido[2,1-a]-phthalazine-1-carboxylic acid were added to a solution of 5.6 g of potassium hydroxide in 60 ml of methanol, whereupon the mixture was heated to boiling under reflux for 25 hours. The solvent was then removed in a vacuum and the residue was taken up in 60 ml of water. The product was precipitated by the addition of 2N hydrochloric acid. The crystals were filtered off under suction, washed with water and dried in a vacuum. There was obtained 3.32 g of 9-chloro-6-imino-4-oxo-3-phenyl-6H-pyrido[2,1-a]isoindole-1-carboxylic acid as yellowish crystals with a m.p. of 266°-268° (decomposition).

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 25 hours
  3. customThe solvent was then removed in a vacuum
  4. customThe product was precipitated by the addition of 2N hydrochloric acid
  5. filtrationThe crystals were filtered off under suction
  6. washwashed with water
  7. customdried in a vacuum

Sources & evidence

ORD record
ord-c497508812974ddfb44f924ec47a5805
Source dataset
uspto-grants-1992_09
Patent number
US05143912

Reaction notes

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