| Popis: |
Abstract 3‐Chloroquinoline‐2,4‐diones react with cyanide ions in dimethyl formamide to give 3‐cyanoquinoline‐2,4‐diones in small yields due to the strong hindrance of the substituent at the C‐3 atom. Good yields can be achieved if the substituent at this position is the methyl group. In the methanol solution, the reaction proceeds by an addition mechanism to form 2‐oxo‐1a,2,3,7b‐tetrahydrooxireno[2,3‐c]quinoline‐7b‐carbonitriles, from which 4‐hydroxy‐3‐methoxy‐2‐oxo‐1,2,3,4‐tetrahydroquinoline‐4‐carbonitriles are subsequently formed by opening of the epoxide ring with methanol. Some minor products of these reactions have also been isolated. The 1H, 13C and 15N NMR spectra of the prepared compounds were measured, and all resonances were assigned using appropriate two‐dimensional spectra. |
