Water → 1-p-Tolyl-6-(2-p-tolyl-2H-pyrazol-3-yl)-1H-benzoimidazole

Participants

Reaction Steps

To a mixture of 6-bromo-1-p-tolyl-1H-benzo[d]imidazole (intermediate F) (100 mg, 348 μmol) and 1-p-tolyl-1H-pyrazol-5-ylboronic acid (intermediate B) (91.5 mg, 453 μmol) in 1,2-dimethoxyethane (3 ml) was added 2M sodium carbonate solution (696 μl, 1.39 mmol) and the reaction mixture was purged with argon for 10 min in an ultrasonic bath. To the stirred mixture tetrakis(triphenylphosphine)palladium(0) (80.5 mg, 69.6 μmol) was added at room temperature and the reaction mixture was allowed to stir under reflux conditions for 15 h. The reaction mixture was cooled to room temperature, poured into water (20 ml) and extracted with ethyl acetate (2×20 ml). The combined organic layers were washed with brine (1×20 ml), dried (MgSO4) and evaporated. The crude material (200 mg) was purified by flash chromatography on silica gel (heptane/ethyl acetate 1:1) and trituration from diethyl ether/heptane to yield the title compound as a off-white solid (55 mg, 43%), MS (ISP) m/z=365.2 [(M+H)+], mp 165° C.

Provenance & Evidence