N-bromobutanimide → Ethyl 6-oxo-2-(trifluoromethyl)-1,6-dihydropyridine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a suspension of 1,4,5,6-tetrahydro-6-oxo-2-(trifluoromethyl)-3-pyridinecarboxylic acid ethyl ester (136.15 g, 0.57 mol) in tetrachloromethane (450 mL) was added N-bromosuccinimide (113 g, 0.60 mol). The temperature was slowly raised with stirring to 70° C. and reflux temperature was maintained for 20 h. The mixture was cooled and extracted with water (1000 mL) and dichlormethane (1000 mL). The water phase was extracted twice more with dichloromethane (2×500 mL) and the dichloromethane phases washed with water (2×1000 mL) and dried with MgSO4. Removal of the solvents yielded the title compound (153.4 g), which was used without further purification in the next reaction.

Provenance & Evidence