| abstract |
Preparation of sterically hindered amine ethers. The compounds of the invention correspond to formula I, in which R is an organic linking group containing 2-500 carbon atoms that forms, together with the carbon atoms to which it is directly connected and the nitrogen atom, a substituted 5-, 6-, or 7-membered acidic ring structure. R {sub, 1}, R {sub, 2}, R {sub, 3}, R {sub, 4}, R {sub, 5}, R {sub, 6}, R {sub, 7} and R {sub, 8} have the meaning set forth in the specification and in the claims. The process is characterized in that a compound of formula II is oxidized in the presence of a solvent, choosing the oxidant from oxygen, peroxides, nitrates, permanganates or chlorates. The compounds of formula I, and their corresponding hydrogenated and / or halogenated compounds, are suitable as stabilizers for organic materials against degradation by light, oxygen and / or heat or yellowing; some are also active as flame retardants. |