2,5-Difluorobenzohydrazide → Toluene-4-sulfonic acid 3-tert-butyl-7-(2,5-difluorophenyl)-4-methylpyrazolo[1,5-d][1,2,4]triazin-2-yl ester

Participants

Reaction Conditions

Reaction Steps

5-Acetyl-4-tert-butyl-3-(4-methylphenyl)sulfonyloxypyrazole (0.4 g, 1.19 mmol) was dissolved in xylene (20 ml) with 2,5-difluorobenzoic hydrazide (0.225 g, 1.31 mmol) and heated under reflux for 14 h. The xylene was removed by evaporation and replaced with Dowtherm A (15 ml) and heated at 180° C. for 4 h. The reaction mixture was allowed to cool to room temperature and poured directly onto a silica column and eluted with dichloromethane then 1-5% ethyl acetate/dichloromethane to give the required product (0.3 g) as a white solid. 1H NMR (360 MHz, CDCl3) δ 1.64 (9H, s), 2.42 (3H, s), 3.11 (3H, s), 7.11-7.83 (8H, m); MS (ES+) m/e 473 [MH]+.

Provenance & Evidence