Allyl bromide → 5-[2-Allyloxy-5-(4-methylpiperazinylsulphonyl)phenyl]-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

HRID 1655262Notes

Reaction equation

HRID 1655262 reaction equation
[CH2:1](Br)[CH:2]=[CH2:3].[OH:5][C:6]1[CH:11]=[CH:10][C:9]([S:12]([N:15]2[CH2:20][CH2:19][N:18]([CH3:21])[CH2:17][CH2:16]2)(=[O:14])=[O:13])=[CH:8][C:7]=1[C:22]1[NH:23][C:24](=[O:35])[C:25]2[N:30]([CH3:31])[N:29]=[C:28]([CH2:32][CH2:33][CH3:34])[C:26]=2[N:27]=1.C(=O)([O-])[O-].[K+].[K+]>CC(=O)CC.CC(C)=O>[CH2:1]([O:5][C:6]1[CH:11]=[CH:10][C:9]([S:12]([N:15]2[CH2:20][CH2:19][N:18]([CH3:21])[CH2:17][CH2:16]2)(=[O:13])=[O:14])=[CH:8][C:7]=1[C:22]1[NH:23][C:24](=[O:35])[C:25]2[N:30]([CH3:31])[N:29]=[C:28]([CH2:32][CH2:33][CH3:34])[C:26]=2[N:27]=1)[CH:2]=[CH2:3]

Participants

6

Reactant 3

HCID 7841Allyl bromideHCID 11430Potassium CarbonateHCID 135565516o-Desethyl sildenafil

Product 1

HCID 1355441565-[2-Allyloxy-5-(4-methylpiperazinylsulphonyl)phenyl]-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-oneYield 10%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 6569Methyl Ethyl KetoneSolvent

Procedure

Allyl bromide (0.02 ml, 0.00023 mol) was added to a stirred suspension of 5-[2-hydroxy-5-(4-methylpiperazinylsulphonyl)phenyl]-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (0.103 g, 0.00023 mol) and potassium carbonate (0.032 g, 0.00023 mol) in 2-butanone (10 ml) and the mixture heated under reflux for 8 hours. After cooling, the reaction mixture was evaporated under vacuum and the residue suspended in water (20 ml). The aqueous suspension was extracted with ethyl acetate (3×20 ml), the combined extracts dried (Na2SO4) and, after filtration, evaporated under vacuum to give an oil. Column chromatography on silica gel (2 g) using a methanol in dichloromethane elution gradient (0-3%), followed by evaporation under vacuum of appropriate fractions, gave a semi-solid which was dissolved in acetone; evaporation under vacuum of the solution gave the title compound (0.011 g, 10%), m.p. 151°-153° C., Rf 0.5 (silica; dichloromethane, methanol; 95:5), m/e 487 (M+ +1).

Workup

  1. temperaturethe mixture heated
  2. temperatureunder reflux for 8 hours
  3. temperatureAfter cooling
  4. customthe reaction mixture was evaporated under vacuum
  5. extractionThe aqueous suspension was extracted with ethyl acetate (3×20 ml)
  6. dry with materialthe combined extracts dried (Na2SO4)
  7. filtrationafter filtration
  8. customevaporated under vacuum
  9. customto give an oil
  10. washa methanol in dichloromethane elution gradient (0-3%)
  11. customfollowed by evaporation under vacuum of appropriate fractions
  12. customgave a semi-solid which
  13. customevaporation under vacuum of the solution

Sources & evidence

ORD record
ord-6dd9a98b019f475e9bf48a072a4bfd39
Source dataset
uspto-grants-1993_10
Patent number
US05250534

Reaction notes

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