Lithium Hexamethyldisilazide → 2,6-Difluoro-N-(1-{[4-iodo-2-(trifluoromethyl)phenyl]methyl}-1H-pyrazol-3-yl)benzamide

Participants

Reaction Steps

To a solution of 2,6-difluoro-N-1H-pyrazol-3-ylbenzamide (for a preparation see Intermediate 9)(2.65 g, 11.9 mmol) in THF (20 ml) was added 1.0 lithium bis(trimethylsilyl)amide in THF (7.3 ml, 7.30 mmol, Aldrich) and stirred for 15 min. To the solution was added a solution of 1-(bromomethyl)-4-iodo-2-(trifluoromethyl)benzene (1.62 g, 4.44 mmol) in THF (10 ml). The resulting orange solution was stirred at ambient temperature under nitrogen overnight. The solvent was removed in vacuo and the residue partitioned between ethyl acetate (200 ml) and saturated aqueous sodium hydrogen carbonate (150 ml). The phases were separated and the aqueous phase washed with ethyl acetate (50 ml). The combined organic phases were dried (MgSO4), filtered and the solvent removed in vacuo. The residue was loaded in dichloromethane and purified on silica 100 g×2 using 0-50% ethyl acetate-cyclohexane. The appropriate fractions were combined and evaporated in vacuo to give the title compound as a white foam (1.3 g). LCMS: (System 4) MH+=508, tRET=3.22 min.

Provenance & Evidence