To a mixture of 2,6-difluoro-N-[3-(5-formyl-1H-benzimidazol-2-yl)-1H-pyrazol-4-yl]-benzamide (50 mg, 0.14 mmol) in anhydrous THF (1.5 mL) stirring at ambient temperature was successively added 3 Å molecular sieves, piperazine-1-carboxylic acid tert-butyl ester (52 mg, 0.28 mmol) and sodium triacetoxy borohydride (90 mg, 0.42 mmol). The mixture was stirred for 4 h, MeOH (3 ml) added and then the mixture was reduced in vacuo. The residue was taken up in EtOAc, washed with brine, dried (MgSO4), reduced in vacuo and then purified through preparative LC/MS to give the title compound (84 mg) as a yellow oil. (LC/MS: Rt 2.22, [M+H]+ 538.15).
