Synthesis of new organic phosphites containing sterically hindered, piperidine groups

The synthesis of several phosphites with sterically hindered piperidine groups which are potential stabilizers for synthetic polymers is described. The reaction of phosphorous acid hexaethyltriamide (1) with the 4-hydroxypiperidine compounds 2 and 3 in a 1:1 and 1:2 ratio gives the phosphorous acid monoester diamides 4 and 5 and phosphorous acid diester monoamides 6 and 7, respectively, These compounds can be selectively hydrolyzed to the phosphorous acid diesters 8 and 9 and to the phosphorous acid monoesters 14 and 15. The new phosphorous acid ester amides 4, 5, 6 and 7 are useful building blocks for the synthesis of phosphites with sterically hindered piperidine moieties. Several representatives of this class of compounds are described.