Piperidine → Piperiacetildenafil

HRID 21924Notes

Reaction equation

HRID 21924 reaction equation
[NH:1]1[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.Br[CH2:8][C:9]([C:11]1[CH:12]=[CH:13][C:14]([O:31][CH2:32][CH3:33])=[C:15]([C:17]2[NH:18][C:19](=[O:30])[C:20]3[N:25]([CH3:26])[N:24]=[C:23]([CH2:27][CH2:28][CH3:29])[C:21]=3[N:22]=2)[CH:16]=1)=[O:10].C(=O)([O-])[O-].[K+].[K+]>C(#N)C>[CH2:32]([O:31][C:14]1[CH:13]=[CH:12][C:11]([C:9](=[O:10])[CH2:8][N:1]2[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]2)=[CH:16][C:15]=1[C:17]1[NH:18][C:19](=[O:30])[C:20]2[N:25]([CH3:26])[N:24]=[C:23]([CH2:27][CH2:28][CH3:29])[C:21]=2[N:22]=1)[CH3:33]

Participants

5

Reactant 3

HCID 8082PiperidineHCID 11430Potassium CarbonateHCID 1357385501,4-Dihydro-5-[5-bromoacetyl)-2-ethoxyphenyl]-1-methyl-3-propyl-7H-pyrazolo[4,3-d]pyrimidin-7-one

Product 1

HCID 135564757PiperiacetildenafilYield 28%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

Piperidine (0.22 ml, 0.0022 mol) was added to a stirred suspension of 5-(5-bromoacetyl-2-ethoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (Preparation 8, 0.95 g, 0.0022 mol) and anhydrous potassium carbonate (0.6 g, 0.0044 mol) in acetonitrile (50 ml) at room temperature. After 18 hours the mixture was evaporated under vacuum, the residue dissolved in water (50 ml) and the solution extracted with ethyl acetate (3×30 ml). The organic extracts were combined, washed with brine (3×20 ml), dried (Na2SO4) and evaporated under vacuum. The resulting yellow solid was chromatographed on silica gel (12g), using a methanol in dichloromethane elution gradient (0-2% methanol), to give an off-white solid. Crystallisation from ethyl acetate-hexane gave the title compound as an off-white powder (0.27 g, 28%), m.p. 149°-151° C. Found: C,66.13; H,6.90; N,15.95. C24H31N5O5 requires C,65,88; H,7.14; N,16.01%.

Workup

  1. customAfter 18 hours the mixture was evaporated under vacuum
  2. dissolutionthe residue dissolved in water (50 ml)
  3. extractionthe solution extracted with ethyl acetate (3×30 ml)
  4. washwashed with brine (3×20 ml)
  5. dry with materialdried (Na2SO4)
  6. customevaporated under vacuum
  7. customThe resulting yellow solid was chromatographed on silica gel (12g)
  8. washa methanol in dichloromethane elution gradient (0-2% methanol)
  9. customto give an off-white solid
  10. customCrystallisation from ethyl acetate-hexane

Sources & evidence

ORD record
ord-63913ca8d35f4e0797208f116ed09fcf
Source dataset
uspto-grants-1995_06
Patent number
US05426107

Reaction notes

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