Mario Secci

Novel reactions of carbon suboxide. IV: Synthesis of some N-hydroxy-2-oxo-2H-1-benzopyran-3-carboxamides

Abstract Some N-hydroxy-2-oxo-2H-1-benzopyran-3-carboxamides have been prepared by reaction of carbon suboxide with 2-hydroxyaryloximes.

One-step synthesis of new 3-oxa- or 3-azabicyclo[3.2.0]hept-5-en-2,7-dione and 5,9-dioxa- or 5,9-diazabicyclo[5.3.0]dec-1-en-3-methyliden-6,8-dione derivatives☆

In this work we describe the synthesis of new compounds of a 3-oxa- or 3-azabicyclo[3.2.0]hept-5-en-2,7-dione (3a–d) and 5,9-dioxa- or 5,9-diazabicyclo[5.3.0]dec-1-en-3-methyliden-6,8-dione (4a–d) type with potential biological activity, obtained from the reaction of 2-propyn-1-ol or 2-propynylamine derivatives (1a–d) with carbon suboxide (2) in various molar ratios.

Novel reactions of carbon suboxide. Part 8. Kinetic study of the reaction with substituted 2-hydroxybenzaldehyde oximes

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 suboxide on the phenol hydroxy group.