Cyclic diamides. II. Syntheses and polymerizations of perhydro‐1,5‐diazocine‐2,4‐dione and its derivatives

One isomer, perhydro‐1,5‐diazocine‐2,4‐dione, was obtained exclusively by the double Beckmann‐rearrangement reactions of cyclohexane‐1,3‐dione dioxime. It is suggested that the other possible isomer was decomposed by a transannular reaction. Perhydro‐1,5‐diazocine‐2,4‐dione was polymerized in the solid state in the presence of water vapor and produced polytrimethylenemalonamide. Further, this monomer was polymerized in the molten state without water. 7‐Methyl‐ and 7,7‐dimethyl‐perhydro‐1,5‐diazocine‐2,4‐dione were prepared, and the latter was polymerized in molten state. Differential thermal analyses of the monomer and x‐ray diffraction measurements of the polymers were carried out.