Nifedipine → Dehydronifedipine

HRID 1018521Notes

Reaction equation

HRID 1018521 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:10]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=2[N+:17]([O-:19])=[O:18])[C:9]([C:20]([O:22][CH3:23])=[O:21])=[C:8]([CH3:24])[NH:7][C:6]=1[CH3:25])=[O:4]>C(O)(=O)C>[CH3:23][O:22][C:20]([C:9]1[C:8]([CH3:24])=[N:7][C:6]([CH3:25])=[C:5]([C:3]([O:2][CH3:1])=[O:4])[C:10]=1[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=1[N+:17]([O-:19])=[O:18])=[O:21]

Participants

3

Reactant 1

HCID 4485Nifedipine

Product 1

HCID 128753DehydronifedipineYield 83%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Over a boiling solution of 3 kg (8.7 mol) of 2,6-dimethyl-4-(2nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3,5-dimethyl ester in 8,251 of acetic acid, 870 g (8.7 mol) of CrO3 were portionwise added, with stirring. When the addition was complete, the reaction mixture was refluxed with stirring for one additional hour. When the mixture reached the room temperature, it was slowly poured, with stirring, over 22.5 1 of a mixture of 25% aq. H4NOH and ice (2:1), and the product precipitated. The solid was isolated by filtration, washed with water until neutral pH, and crystallised (mp 99-101° C., MeOH) with a yield of 83%.

Workup

  1. additionWhen the addition
  2. temperaturethe reaction mixture was refluxed
  3. stirringwith stirring for one additional hour
  4. customthe room temperature, it
  5. additionwas slowly poured
  6. stirringwith stirring, over 22.5 1 of a mixture of 25% aq. H4NOH and ice (2:1)
  7. customthe product precipitated
  8. customThe solid was isolated by filtration
  9. washwashed with water until neutral pH
  10. customcrystallised (mp 99-101° C., MeOH) with a yield of 83%

Sources & evidence

ORD record
ord-d1ecadecd6914e12a6c7cfe909c04d04
Source dataset
uspto-grants-2002_11
Patent number
US06482841B1

Reaction notes

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