New solventless and metal-free synthesis of the antiepileptic drug 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxamide (Rufinamide) and analogues

This work presents a new synthesis of the antiepileptic drug rufinamide—1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxamide) in chemical form—and some analogue compounds, through a one-pot reaction employing a solventless, metal-free catalysis and without any reducing reagent. The great novelty presented is the synthesis of 4-trichloroacetyl-1-(2,6-difluorobenzyl/benzyl/4-methoxybenzyl)-5-methyl(phenyl)-1H-1,2,3-triazoles as new precursors from a regioselective 1,3-dipolar cycloaddition reaction between 1,1,1-trichloro-4-alkoxyalk-3-en-2-ones and some benzyl azides, which are converted into rufinamide and the analogues by an addition–elimination reaction with an aqueous solution of NH4OH in good yields (42–52%).