Dimethylformamide → Rufinamide

Participants

Reaction Conditions

Reaction Steps

75.4 ml of Oxalyl chloride (919.8 mmol) were added at 25° C. to a stirred suspension of (2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxylic acid (200.0 g, 836.2 mmol) in THF (500 ml) and DMF (0.5 ml). The stirring was maintained for 4 hr at 25° C. until the solid dissolved. Afterwards, 1000 ml of THF were added and reduced pressure (200-250 mbar) was applied leading to the distillation of 300 ml of THF and to the maintenance of the internal temperature at about 25-35° C. After that, the mixture was slightly cool to 25° C. and 160 g of ammonium chloride were added in portions followed by slow addition of 400 ml of an 8% NaHCO3 solution and 176 g of solid NaHCO3 (vigorous stirring was also needed to prevent frothing). The heterogeneous mixture was stirred for 2 hr, filtered and the solid re-suspended in 1 L water. The solid was filtered and dried (at 200 mbar/50° C.) yielding 130 g (65.3%) of 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxamide, as a white solid in form R5.

Provenance & Evidence