Potassium tert-butoxide → Propyl 5-cyano-2-methyl-4-(2-methyl-4-oxo-4H-chromen-8-yl)-6-(trifluoromethyl)-1,4-dihydropyridine-3-carboxylate

Participants

Reaction Steps

A solution of 295 mg (0.94 mmol) of propyl 2-[(2-methyl-4-oxo-4H-chromen-8-yl)methylene]-3-oxobutanoate in 20 ml of 2-propanol is mixed with 127.71 mg (0.94 mmol) of 3-amino-4,4,4-trifluorobut-2-enenitrile [preparation in analogy to K. Krespan, J. Org. Chem. 34, 4245 (1969)] and 15.8 mg (0.14 mmol) of potassium tert-butoxide and stirred under reflux for 12 h. After cooling, the mixture is concentrated. The residue is purified on an Analogix cartridge (F12M) (mobile phase: cyclohexane/ethyl acetate 2:1). After concentration of the product fractions, the residue is crystallized from diethyl ether. 88.4 mg (20.7% of theory) of the title compound are obtained as white crystals.

Provenance & Evidence