1.6 g (3.98 mmol) of 4-[1-(4-methoxybenzyl)-3-(3-nitrophenyl)-1H-pyrazol-4-yl]-pyrimidin-2-amine were dissolved in a mixture of 100 ml of dioxane and 30 ml of water and 2.12 g (40 mmol) of ammonium chloride and 1.05 g (16 mmol) of metallic zinc were added successively. The reaction mixture was stirred at 100° C. for 6 hours. The suspension was then filtered through a celite pad and the filtrate evaporated. The residue was partitioned between dichloromethane and aqueous sodium hydrogenocarbonate, dried over sodium sulphate and evaporated again, giving 1 g (67%) of the title compound.
