6-(tert-Butyl-dimethylsilyloxy)-2-(3,5-dichlorophenyl)-dihydro-pyrazolo[1,2-alpha][1,2,4]triazole-1,3-dione → 2-(3,5-Dichlorophenyl)-6-hydroxy-dihydro-pyrazolo[1,2-alpha][1,2,4]triazole-1,3-dione

HRID 1838461Notes

Reaction equation

[Si]([O:8][CH:9]1[CH2:26][N:12]2[C:13](=[O:25])[N:14]([C:17]3[CH:22]=[C:21]([Cl:23])[CH:20]=[C:19]([Cl:24])[CH:18]=3)[C:15](=[O:16])[N:11]2[CH2:10]1)(C(C)(C)C)(C)C>F.C(#N)C>[Cl:23][C:21]1[CH:22]=[C:17]([N:14]2[C:15](=[O:16])[N:11]3[CH2:10][CH:9]([OH:8])[CH2:26][N:12]3[C:13]2=[O:25])[CH:18]=[C:19]([Cl:24])[CH:20]=1

Participants

Conditions

Temperature: 55 °C

Procedure

A solution of 6-(tert-Butyl-dimethylsilyloxy)-2-(3,5-dichlorophenyl)-dihydro-pyrazolo[1,2-α][1,2,4]triazole-1,3-dione (1.9 g, 4.56 mmol) (Preparation 5) in a mixture of 50% hydrofluoric acid (2 ml) and acetonitrile (80 ml) was heated for 7 h at 50-60° C. in a Teflon flask. The solvent was removed under vacuum and the residue crystallized in diethyl ether to yield the above compound as a white solid (1.1 g, mp=160° C.). 1H NMR (CDCl3):7.49 (2H, m), 7.38 (1H, m), 4.54 (1H, br s), 3.98 (2H, d, J=12 Hz), 3.49 (2H, dd, J1=12 Hz, J2=2.1 Hz), 3.10 (1H, br s).

Workup

customThe solvent was removed under vacuum
customthe residue crystallized in diethyl ether

Sources & evidence

ORD record: ord-427ceb456f1e4262a2b4dd7da5d3f772
Source dataset: uspto-grants-2004_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06673825B2

Reaction notes

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