Rufinamide. Antiepileptic, Treatment of neurogenic pain.

Rufinamide has been obtained by several related ways: 1) Cyclization of 2,6-difluorobenzyl azide (I) with 2-propynoic acid (II) i n hot toluene gives 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxylic a cid (III), which is treated with refluxing SOCl2 to yield the corresponding acyl chloride (IV). Finally, this compound is treated with aqueous concent rated NH4OH (I). Scheme 1. 2) Cyclization of 2,6-difluorobenzyl azide (I) with 2-chloroacrylonitrile ( V) in hot water or n-heptane gives 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole -4-carbonitrile (VI), which is treated with NaOH in hot toluene/water (2). Scheme 1. 3) Esterification of 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxylic acid (III) with methanol/H2SO4 gives the corresponding methyl ester (VII), which is treated with NH3 in hot methanol (3). Scheme 1.