Products are described which are obtainable by reacting compounds of formula I with compounds of formula IIa or/and IIb and IIIa or/and IIIb and additionally, where appropriate, IV ##STR1## wherein the general symbols are as defined in claim 1, the compound of formula I being, for example, methyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, the compound of formula IIa being, for example, diethanolamine, the compound of formula IIIa being, for example, methyl oleate, and the compound of formula IV being, for example, sulfur. The cited products can be used as liquid antioxidants in organic materials.