Piperidine derivatives which are stabilizers for synthetic polymers

Claim 1

A compound of the formula ##STR35## or an acid addition salt thereof, in which R 1 represents (a) hydrogen, (b) C 1 -C 12 -alkyl, (c) --CH 2 CN (d) C 3 -C 12 -alkenyl, (e) C 3 -C 12 -alkinyl, (f) benzyl, (g) benzyl substituted by 1 to 3 C 1 -C 4 -alkyl radicals, (h) hydroxybenzyl, (i) hydroxybenzyl substituted by 1 to 3 C 1 -C 4 -alkyl radicals, (j) a --COR 8 , --COOR 8 , --CH 2 COOR 8 or --CONR 8 R 9 radical in which R 8 and R 9 , which may be identical or different, represent (1) linear or branched C 1 -C 12 -alkyl, (2) C 3 -C 12 -alkenyl, (3) C 5 -C 12 -cycloalkyl, (4) phenyl, (5) phenyl substituted by 1 to 3 C 1 -C 8 -alkyl radicals, (6) hydroxyphenyl, (7) hydroxyphenyl substituted by 1 to 3 C 1 -C 8 -alkyl radicals, (8) C 7 -C 12 -aralkyl, or (9) 2,2,6,6-tetramethyl-piperidin-4-yl, (k) a ##STR36## radical, in which R 10 is hydrogen, methyl or phenyl and R 11 is hydrogen, --R 8 , --COR 8 or --CONR 8 R 9 , in which R 8 and R 9 are as defined above, or (l) a ##STR37## radical; R 2 , R 3 , R 6 and R 7 , which may be identical or different, are alkyl containing 1 to 6 C atoms; R 4 and R 5 , which may be identical or different, are hydrogen or alkyl containing 1 to 6 C atoms; A is ##STR38## radical, in which R 12 is a radical of the formula ##STR39## in which R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are as defined above, R 13 is hydrogen, linear or branched C 1 -C 20 -alkyl, C 5 -C 12 -cycloalkyl, phenyl, o-, m- or p-toluyl, o-, m- or p-hydroxyphenyl, 3,5-di-t-butyl-4-hydroxy-phenyl, o-, m- or p-methoxyphenyl, o-, m- or p-ethoxyphenyl, benzyl, 4-methylbenzyl, 4-t-butylbenzyl, 4-hydroxybenzyl, 3,5-di-t-butyl-4-hydroxybenzyl, 4-methoxybenzyl, 4-ethoxybenzyl, or a group of the formula ##STR40## or A is a heterocyclic radical selected from the group consisting of pyrrolidin-1-yl, piperidin-1-yl, morpholin-4-yl, piperazin-1-yl, 4-methyl-piperazin-1-yl, hexahydroazepin-1-yl, homopiperazin-1-yl and 4-methyl-homopiperazin-1-yl.