Potassium Bicarbonate → 5-(2,6-Difluorophenyl)-N,N-dimethyl-4,5-dihydroisoxazole-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

A 1000-mL round bottom flask equipped with a mechanical stirrer, thermometer and addition funnel was charged with 2-(dimethylamino)-N-hydroxy-2-oxoethanimidoyl chloride (94.0 g, 0.62 mol) and a solution of 2,6-difluorostyrene (84.0 g, 0.60 mol) in chlorobenzene (275 g). The reaction mixture was cooled to 10° C., and a solution of potassium bicarbonate (70 g, 0.70 mol) in water (350 mL) was added dropwise over 1 h while maintaining the reaction temperature between 10 to 15° C. When gas chromatography analysis of the reaction mixture showed about 3% of 2-(dimethylamino)-N-hydroxy-2-oxo-ethanimidoyl chloride remaining, water (200 mL) was added to the reaction mixture. The layers were separated, and the organic layer was washed with water (300 mL) and concentrated under reduced pressure. Toluene was added to the resulting residu, and the mixture was again concentrated under reduced pressure to provide the title compound as an oil (144 g).

Provenance & Evidence