Ethyl 4-oxo-1,4-dihydrocinnoline-3-carboxylate → 4-Oxo-1,4,5,6,7,8-hexahydrocinnoline-3-carboxylic acid ethyl ester

HRID 567702Notes

Reaction equation

HRID 567702 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:15](=[O:16])[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[NH:8][N:7]=1)=[O:5])[CH3:2].[H][H]>FC(F)(F)C(O)=O.[Pt]=O>[CH2:1]([O:3][C:4]([C:6]1[C:15](=[O:16])[C:14]2[CH2:13][CH2:12][CH2:11][CH2:10][C:9]=2[NH:8][N:7]=1)=[O:5])[CH3:2]

Participants

5

Reactant 2

HCID 23320177Ethyl 4-oxo-1,4-dihydrocinnoline-3-carboxylateHCID 178418361HCID 178418361, compound

Product 1

HCID 541078584-Oxo-1,4,5,6,7,8-hexahydrocinnoline-3-carboxylic acid ethyl esterYield 61.1%

Reagents, catalysts & solvents 2

HCID 82844Platinum oxide (PtO)CatalystHCID 6422Trifluoroacetic acidSolvent

Procedure

To 4-oxo-1,4-dihydrocinnoline-3-carboxylic acid ethyl ester (4.5 g) dissolved in trifluoroacetic acid (20 ml) was added platinum oxide (0.2 g). The reaction mixture was hydrogenated at 50 psi until no further uptake of hydrogen was observed. The catalyst was collected by filtration, the filtrate was poured onto ice, the pH was raised to pH6 with base, the resulting precipitate was collected by filtration, washed with water and dried to give a solid (2.8 g, 61%). δH (250 MHz; DMSO-d6) 1.26 (3H, t, J=7 Hz, CH3), 1.68 (4H, m, CH2), 2.33 (2H, t, J=5.5 Hz, CH2), 2.62 (2H, t, J=5.5 Hz, CH2), 4.25 (2H, t, J=7 Hz, CH2), 13.19 (1H, br s, NH), m/z (ESP+) 223 (MH+).

Workup

  1. filtrationThe catalyst was collected by filtration
  2. additionthe filtrate was poured onto ice
  3. temperaturethe pH was raised to pH6 with base
  4. filtrationthe resulting precipitate was collected by filtration
  5. washwashed with water
  6. customdried

Sources & evidence

ORD record
ord-0033c0a40c9e421fa38b46d061484288
Source dataset
uspto-grants-2001_01
Patent number
US06180630B2

Reaction notes

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