1,4-Dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyrazinedi-carboxylic acid, dimethyl ester → 4-(3-Aminophenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyrazinedicarboxylic acid, dimethyl ester

HRID 566902Notes

Reaction equation

HRID 566902 reaction equation
[CH3:1][C:2]1[NH:3][C:4]([CH3:25])=[C:5]([C:21]([O:23][CH3:24])=[O:22])[N:6]([C:12]2[CH:17]=[CH:16][CH:15]=[C:14]([N+:18]([O-])=O)[CH:13]=2)[C:7]=1[C:8]([O:10][CH3:11])=[O:9]>CO.O.Cl.[Fe]>[NH2:18][C:14]1[CH:13]=[C:12]([N:6]2[C:5]([C:21]([O:23][CH3:24])=[O:22])=[C:4]([CH3:25])[NH:3][C:2]([CH3:1])=[C:7]2[C:8]([O:10][CH3:11])=[O:9])[CH:17]=[CH:16][CH:15]=1

Participants

6

Reactant 1

HCID 155242361,4-Dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyrazinedi-carboxylic acid, dimethyl ester

Product 1

HCID 155242374-(3-Aminophenyl)-1,4-dihydro-2,6-dimethyl-3,5-pyrazinedicarboxylic acid, dimethyl esterYield 88%

Reagents, catalysts & solvents 4

HCID 313Hydrochloric AcidCatalystHCID 23925IronCatalystHCID 887MethanolSolventHCID 962WaterSolvent

Procedure

1,4-Dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyrazinedi-carboxylic acid, dimethyl ester (219 mg, 0.63 mmol) was dissolved in 30 mL methanol containing 3 mL of water in a flask equipped with a mechanical stirrer. Iron powder (300 mg) was added, followed by one drop of 37% hydrochloric acid. The whole mixture was refluxed moderately with mechanical stirring for 3.5 hours. Usual extractive work up furnished the title compound as yellow solid (176 mg, 88%): mp 212-213° C.; 1H-NMR (CDCl3) δ 6.91 (t, 1H, J=8.0 Hz), 6.20 (dd, 1H, J=7.8, 2.0 Hz), 6.11 (dd, 1H, J=8.2, 2.3 Hz), 6.00 (t, 1H, J=2.2 Hz), 5.93 (s, 1H), 3.77 (s, 6H), and 2.38 (s, 6H); 13C-NMR (CDCl3) δ 166.8, 152.0, 148.5, 146.9, 129.6, 109.5, 107.8, 104.2, 100.3, 51.8, and 17.9.

Workup

  1. customequipped with a mechanical stirrer
  2. temperatureThe whole mixture was refluxed moderately

Sources & evidence

ORD record
ord-9684a53efa9d4fb892ed2cdb947643aa
Source dataset
uspto-grants-2001_01
Patent number
US06177429B1

Reaction notes

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