Ammonium formate → 4,6-Dihydro-4-oxo-3-phenylpyrido[2,1-a]isoindole-1-carboxylic acid

HRID 256687Notes

Reaction equation

HRID 256687 reaction equation
Cl[C:2]1[CH:10]=[C:9]2[C:5]([C:6](=N)[N:7]3[C:14](=[O:15])[C:13]([C:16]4[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=4)=[CH:12][C:11]([C:22]([OH:24])=[O:23])=[C:8]32)=[CH:4][CH:3]=1.C([O-])=O.[NH4+]>CO.[Pd]>[O:15]=[C:14]1[N:7]2[CH2:6][C:5]3[C:9]([C:8]2=[C:11]([C:22]([OH:24])=[O:23])[CH:12]=[C:13]1[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)=[CH:10][CH:2]=[CH:3][CH:4]=3

Participants

5

Reactant 2

HCID 2723923Ammonium formate2×HCID 189570979-chloro-6-imino-4-oxo-3-phenyl-6H-pyrido[2,1-a]isoindole-1-carboxylic acid

Product 1

HCID 156408234,6-Dihydro-4-oxo-3-phenylpyrido[2,1-a]isoindole-1-carboxylic acidYield 80.2%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent

Procedure

A suspension of 18.1 g of 9-chloro-6-imino-4-oxo-3-phenyl-6H-pyrido[2,1-a]isoindole-1-carboxylic acid and 18 g of 10 percent palladium/carbon in 900 ml of methanol was treated with 16.3 g of ammonium formate and then heated to boiling under reflux for 90 minutes. The treatment with ammonium formate and subsequent heating were repeated once, whereupon the catalyst was filtered off, the solvent was removed in a vacuum and the residue was taken up in 150 ml of water. The mixture was acidified with 1N hydrochloric acid, the crystals were filtered off under suction and washed with water. There were obtained 12.55 g of 4,6-dihydro-4-oxo-3-phenylpyrido[2,1-a]isoindole-1-carboxylic acid with a m.p. of 277°-278° (decomposition).

Workup

  1. temperatureheated
  2. temperatureunder reflux for 90 minutes
  3. filtrationwas filtered off
  4. customthe solvent was removed in a vacuum
  5. filtrationthe crystals were filtered off under suction
  6. washwashed with water

Sources & evidence

ORD record
ord-1d747e6392004100ab354d58b6426c0f
Source dataset
uspto-grants-1993_11
Patent number
US05258387

Reaction notes

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