| 摘要 |
A new process is described for the preparation of a compound of the formula IwhereinR1, R2, R3 and R4, independently of each other, are C1-C8alkyl or C1-C5hydroxyalkyl, or R1 and R2 together with the carbon atom they are attached to are C5-C12cycloalkyl or R3 and R4 together with the carbon atom they are attached to are C5-C12cycloalkyl;R5, R6, R7, R8 and R9, independently of each other, are H, C1-C8alkyl, C2-C8alkenyl, C5-C12aryl, C1-C4haloalkyl, an electron withdrawing group, or C1-C12aryl which is substituted by a residue selected from C1-C4alkyl, C1-C4alkoxy, halogen; and R7 and R8 together may also form a chemical bond; andR is an organic linking group containing 2-500 carbon atoms and forming, together with the carbon atoms it is directly connected to and the nitrogen atom, a substituted, 5-, 6 or 7-membered cyclic ring structure; characterized in that a compound of the formula IIis oxidized. The compound of the formula I can be hydrogenated and/or halogenated by conventional methods.Compounds of the formula I and the corresponding hydrogenated and/or halogenated compounds are well suitable as stabilizers for organic material against degradation by light, oxygen and/or heat or yellowing; some are also active as flame retardants.
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