Citric Acid → Sildenafil Citrate

HRID 1435824Notes

Reaction equation

HRID 1435824 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%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

In a 3-necked flask, sildenafil (5 g, 10 mmol) was dissolved in acetone (100 ml) at reflux. Citric acid (2 g, 10 mmol) was added, and a white precipitate appeared immediately. The reaction mixture was maintained at the reflux temperature for 1 hour and allowed to cool over 3 hours to room temperature. The precipitate was collected, filtered, and dried at 50° C. under 10 mm Hg to give pure sildenafil citrate in 94% yield.

Workup

  1. temperatureat reflux
  2. temperatureThe reaction mixture was maintained at the reflux temperature for 1 hour
  3. temperatureto cool over 3 hours to room temperature
  4. customThe precipitate was collected
  5. filtrationfiltered
  6. customdried at 50° C. under 10 mm Hg

Sources & evidence

ORD record
ord-12ab7e4e5d654d04a34db05ffe10d3d1
Source dataset
uspto-grants-2009_11
Patent number
US07618976B2

Reaction notes

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