Ester and amides having the formula ##STR1## wherein R, R.sup.1 and R.sup.2 are independently lower alkyl or cycloalkyl groups, R.sup.3 is hydrogen, alkyl, cycloalkyl, alkylene, phenyl, phenyl substituted by alkyl groups, alkylthioethyl, thiobis-alkylene, alkyleneoxyalkylene, polyoxyalkylene or a polyvalent cyclic or acyclic hydrocarbon radical, R.sup.4 is hydrogen, lower alkyl, cycloalkyl, R.sup.5 is hydrogen, alkyl, phenyl, phenyl substituted by alkyl groups, alkylene, a polyvalent cyclic or acyclic hydrocarbon radical or alkyleneoxyalkylene, A is lower alkylene, m is 1 to 4 and n is 1 to 6.The compounds are useful as stabilizers of organic materials, especially polyolefins, which deteriorate upon exposure to light and heat.