1-Methylpiperazine → o-Desethyl sildenafil

HRID 2226137Notes

Reaction equation

HRID 2226137 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-5103d220bb934e7ab2d15fd66a536878
Source dataset
uspto-grants-1994_09
Patent number
US05346901

Reaction notes

Loading…