A mixture of 4-(5-iodo-6-trifluoromethyl-pyridazin-3-yl)-piperazine-1-carboxylic acid tert-butyl ester (D10) (0.20 g, 0.436 mmol), o-tolylboronic acid (0.071 g, 0.523 mmol), 1,1′-bis(diphenylphosphino)ferrocenepalladium(II).dichloride, dichloromethane (0.022 g, 0.026 mmol), 1,1′-bis(diphenylphosphino)ferrocene (0.015 g, 0.026 mmol) and potassium phosphate (0.138 g, 0.654 mmol) in dioxane (8.5 ml) was stirred at 80° C. for 16 h. and then at 110° C. for 2 days. The mixture was then filtered through a pad of diatomaceous earth and the solvent was evaporated in vacuo. The residue was purified by column chromatography (silica gel; dichloromethane/methanol 70/30) to yield D11 (0.089 g, 48%) as a yellow solid. C21H25F3N4O2 requires 422; Found 423 (MH+).
