4-(Trifluoromethyl)benzenesulfonamide → N-((3-iodo-1-(methoxymethyl)-1H-pyrazol-4-yl)methylene)-4-(trifluoromethyl)benzenesulfonamide

Participants

Reaction Steps

3-Iodo-1-(methoxymethyl)-1H-pyrazole-4-carbaldehyde (39) (2.0 g, 7.52 mmol) and 4-(trifluoromethyl)benzenesulfonamide (40) (1.69 g, 7.52 mmol) were dissolved in THF (20 mL) under nitrogen. Titanium(IV) ethoxide (7.8 mL, 37.6 mmol) was added via syringe and the reaction stirred for 16 hr at rt. The reaction was poured into brine (50 mL) and filtered through a pad of Celite. The filtrate was extracted with EtOAc (3×50 mL) and the combined organics were washed with brine (100 mL), dried over Na2SO4, and concentrated in vacuo to give N-((3-iodo-1-(methoxymethyl)-1H-pyrazol-4-yl)methylene)-4-(trifluoromethyl)benzenesulfonamide (41) as a clear oil that was used without further purification.

Provenance & Evidence