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

HRID 1885349Notes

Reaction equation

HRID 1885349 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-83b1eb518a3a4cb5ab72301d62ef7a20
Source dataset
uspto-grants-1992_09
Patent number
US05143912

Reaction notes

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