Cesium carbonate → 6-(1-tert-butyl-1H-pyrazol-4-yl)-3-methyl-4-(methylthio)-3H-imidazo[4,5-c]pyridine

Participants

Reaction Steps

To a mixture of 6-chloro-3-methyl-4-(methylthio)-3H-imidazo[4,5-c]pyridine 2.02 and 6-chloro-1-methyl-4-(methylthio)-1H-imidazo[4,5-c]pyridine 2.03 (prepared as previously described, ˜1:2 mixture of regioisomers, 1.25 g, 5.85 mmol),1-tert-butyl-4-(4,4,5,5-tetramethyl-1,3-dioxolan-2-yl)-1H-pyrazole (2.20 g, 8.78 mmol), and Cs2CO3 (5.72 g, 17.6 mmol) was added DME (20 mL) and water (10 mL) and the solution was degassed for 10 min. [1,3-Bis(2,6-Diisopropylphenyl)imidazol-2-ylidene](3-chloropyridyl)palladium(II) dichloride (397 mg, 0.585 mmol) was added and the reaction was heated to 100 deg C. for 1 hour. Upon cooling, the aqueous layer was removed, EtOAc and water were added, and the layers separated. The organic layer was dried (MgSO4), filtered and concentrated. The residue was purified by flash chromatography (EtOAc 0-->5% MeOH gradient) to afford 6-(1-tert-butyl-1H-pyrazol-4-yl)-3-methyl-4-(methylthio)-3H-imidazo[4,5-c]pyridine 2.39 and 6-(1-tert-butyl-1H-pyrazol-4-yl)-3-methyl-4-(methylthio)-3H-imidazo[4,5-c]pyridine 2.40, which were isolated as a mixture and carried directly into the next step.

Provenance & Evidence