Citric Acid → Sildenafil Citrate

HRID 1435825Notes

Reaction equation

HRID 1435825 reaction equation
[CH3:1][CH2:2][CH2:3][C:4]1[C:5]2[N:14]=[C:13]([C:15]3[CH:16]=[C:17]([S:24]([N:27]4[CH2:32][CH2:31][N:30]([CH3:33])[CH2:29][CH2:28]4)(=[O:26])=[O:25])[CH:18]=[CH:19][C:20]=3[O:21][CH2:22][CH3:23])[NH:12][C:10](=[O:11])[C:6]=2[N:7]([CH3:9])[N:8]=1.[C:34]([OH:46])(=[O:45])[CH2:35][C:36]([CH2:41][C:42]([OH:44])=[O:43])([C:38]([OH:40])=[O:39])[OH:37]>CC(C)=O>[CH3:1][CH2:2][CH2:3][C:4]1[C:5]2[N:14]=[C:13]([C:15]3[CH:16]=[C:17]([S:24]([N:27]4[CH2:32][CH2:31][N:30]([CH3:33])[CH2:29][CH2:28]4)(=[O:25])=[O:26])[CH:18]=[CH:19][C:20]=3[O:21][CH2:22][CH3:23])[NH:12][C:10](=[O:11])[C:6]=2[N:7]([CH3:9])[N:8]=1.[CH2:41]([C:36]([OH:37])([C:38]([OH:40])=[O:39])[CH2:35][C:34]([OH:46])=[O:45])[C:42]([OH:44])=[O:43]

Participants

4

Reactant 2

HCID 311Citric AcidHCID 135398744Sildenafil

Product 1

HCID 135413523Sildenafil CitrateYield 94.4%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

In a 3-necked flask, sildenafil (5 g, 10 mmol) and citric acid (2 g, 10 mmol) were suspended in acetone (100 ml). The reaction mixture was heated to reflux and maintained at reflux for 1 hour, thereafter, the reaction mixture was allowed to cool for 3 hours to room temperature. The precipitate was collected by filtration and dried at 50° C. under 10 mm Hg to give pure sildenafil citrate in 94.4% yield.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux
  3. temperaturemaintained
  4. temperatureat reflux for 1 hour
  5. temperatureto cool for 3 hours to room temperature
  6. filtrationThe precipitate was collected by filtration
  7. customdried at 50° C. under 10 mm Hg

Sources & evidence

ORD record
ord-cf1e59e6c389400b8f04d66b84337cb0
Source dataset
uspto-grants-2009_11
Patent number
US07618976B2

Reaction notes

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