1-Methylpiperazine → o-Desethyl sildenafil

HRID 1532115Notes

Reaction equation

HRID 1532115 reaction equation
Cl[S:2]([C:5]1[CH:6]=[CH:7][C:8]([OH:25])=[C:9]([C:11]2[NH:12][C:13](=[O:24])[C:14]3[N:19]([CH3:20])[N:18]=[C:17]([CH2:21][CH2:22][CH3:23])[C:15]=3[N:16]=2)[CH:10]=1)(=[O:4])=[O:3].[CH3:26][N:27]1[CH2:32][CH2:31][NH:30][CH2:29][CH2:28]1>C(O)C>[OH:25][C:8]1[CH:7]=[CH:6][C:5]([S:2]([N:30]2[CH2:31][CH2:32][N:27]([CH3:26])[CH2:28][CH2:29]2)(=[O:4])=[O:3])=[CH:10][C:9]=1[C:11]1[NH:12][C:13](=[O:24])[C:14]2[N:19]([CH3:20])[N:18]=[C:17]([CH2:21][CH2:22][CH3:23])[C:15]=2[N:16]=1

Participants

4

Reactant 2

HCID 531671-MethylpiperazineHCID 135738545Demethylpiperazinyl Desethyl Sildenafil Sulfonyl Chloride

Product 1

HCID 135565516o-Desethyl sildenafilYield 97%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 5-(5-chlorosulphonyl-2-hydroxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (0.235 g, 0.0006 mol) and N-methylpiperazine (0.5 ml, 0.0045 mol) in ethanol (40 ml) was stirred at room temperature for 18 hours. The solution was evaporated under vacuum and the residue partitioned between ethyl acetate (40 ml) and water (40 ml). The fine precipitate was filtered off, washed with water then ethyl acetate, and crystallised from ethyl acetate/DMF to give the title compound as an off-white powder (0.260 g, 49%), m.p.. 283-284° C. Found: C, 53.53; H, 5.89; N, 18.40. C20H26N6O4S requires C, 53.80; H, 5.87; N, 18.82%.

Workup

  1. customThe solution was evaporated under vacuum
  2. customthe residue partitioned between ethyl acetate (40 ml) and water (40 ml)
  3. filtrationThe fine precipitate was filtered off
  4. washwashed with water
  5. customethyl acetate, and crystallised from ethyl acetate/DMF

Sources & evidence

ORD record
ord-76691e0ecf8f474fa238dc57f75019eb
Source dataset
uspto-grants-2001_03
Patent number
US06200980B1

Reaction notes

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