The kinetics of the reaction of carbon suboxide with aryl-substituted 2-hydroxybenzaldehyde oximes to give coumarin derivatives have been studies. A Hammett plot gave a ρ value of ca.–1.5, indicating that the reaction was promoted by electron-releasing groups para to the oxime function. Increasing the dielectric constant of the solvent raises the reaction rate; we have therefore proposed the formation of an ionic intermediate, after fast attack of carbon ...
![2-[(4-methoxyphenyl)iminomethyl]aniline Structure](https://image.chemsrc.com/caspic/445/69339-13-5.png)
