Sodium Hydroxide → Sildenafil

HRID 1435826Notes

Reaction equation

[CH3:1][N:2]1[CH2:7][CH2:6][NH:5][CH2:4][CH2:3]1.[OH-].[Na+].[CH3:10][N:11]1[C:19]2[C:18](=[O:20])[N:17]=[C:16]([C:21]3[CH:22]=[C:23]([S:30](Cl)(=[O:32])=[O:31])[CH:24]=[CH:25][C:26]=3[O:27][CH2:28][CH3:29])[NH:15][C:14]=2[C:13]([CH2:34][CH2:35][CH3:36])=[N:12]1>CC(C)=O>[CH3:36][CH2:35][CH2:34][C:13]1[C:14]2[N:15]=[C:16]([C:21]3[CH:22]=[C:23]([S:30]([N:5]4[CH2:6][CH2:7][N:2]([CH3:1])[CH2:3][CH2:4]4)(=[O:31])=[O:32])[CH:24]=[CH:25][C:26]=3[O:27][CH2:28][CH3:29])[NH:17][C:18](=[O:20])[C:19]=2[N:11]([CH3:10])[N:12]=1

Participants

Conditions

Temperature: 22 °C

Procedure

In a 0.25 L reactor equipped with mechanical stirrer and thermometer, 100 ml of acetone was added. The reactor was maintained at room temperature (22° C.). 5.35 g of N-methyl piperazine (1.1 equivalents) followed by 4.16 g of NaOH solution (47%, 1 equivalent) were added. 20 g of 1-[[3-(4,7-Dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-4-ethoxyphenyl] sulfonyl chloride was added portion-wise (5 g each). The reaction mixture was kept at room temperature with mixing for 1 hour. The reaction mixture was kept at 5° C. for 2 hours. During that period, sildenafil base precipitated. After filtration, the cake was washed with water (50 ml). 29.24 g wet sildenafil base was obtained.

Workup

customIn a 0.25 L reactor equipped with mechanical stirrer
additionwere added
customwas kept at room temperature
additionwith mixing for 1 hour
waitDuring that period
customsildenafil base precipitated
filtrationAfter filtration
washthe cake was washed with water (50 ml)

Sources & evidence

ORD record: ord-0f420e653e3e4f4f8d7c176a4148d0db
Source dataset: uspto-grants-2009_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07618976B2

Reaction notes

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