10.0 g (47.4 mmol) of 5-bromo-4-methyl-1H-indazole and 21.0 g (56.9 mmol) of tert-butyl 4-[(tosyloxy)methyl]piperidin-1-carboxylate were dissolved in 726 ml DMF. To this were added 21.0 g (56.9 mmol) of tetrabutylammonium iodide and 18.5 g (56.9 mmol) of caesium carbonate and the reaction mixture was heated under nitrogen at 80° C. for 1.5 hrs. For the work-up, it was treated with water and ethyl acetate, the organic phase separated and the aqueous phase extracted several times with ethyl acetate. The organic phases were washed with saturated sodium chloride solution, dried over sodium sulphate and concentrated in vacuo. After purification by column chromatography, this yielded the title compound in 5 g yield.
