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

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence