Isopropyl 4,4,4-Trifluoroacetoacetate → Isopropyl 5-cyano-6-methyl-4-(2-methyl-4-oxo-4H-chromen-8-yl)-2-(trifluoromethyl)-1,4-dihydropyridine-3-carboxylate

Participants

Reaction Steps

100 mg (0.53 mmol) of 2-methyl-4-oxo-4H-chromene-8-carbaldehyde are dissolved with 105 mg (0.53 mmol) of isopropyl 4,4,4-trifluoro-3-oxobutanoate, 43.6 mg (0.53 mmol) of 3-aminocrotononitrile and 46 μl (0.79 mmol) of acetic acid in 5 ml of 2-propanol and heated under reflux under argon for 4 h. The solvent is removed in vacuo, and the residue is purified by preparative HPLC. The main product obtained in this way is stirred under reflux in acetic acid overnight. The solution is concentrated and the residue is recrystallized from diethyl ether. 75 mg (33% of theory) of the title compound are obtained as a white solid.

Provenance & Evidence