2-Phenyl-indole derivatives of the general formula: ##STR1## wherein R.sub.1 represents a hydroxy radical, a branched- or straight-chain alkyloxy group containing from 1 to 12 carbon atoms, an allyloxy or propargyloxy radical, a cylcoalkyloxy radical containing from 5 to 7 carbon atoms or a benzyloxy radical, R.sub.2 represents a hydroxy radical, an ethoxy, methylsulphonyloxy, benzenesulphonyloxy or toluenesulphonyloxy group and R.sub.3 represents a hydrogen atom, a hydroxy radical or a methoxy group. The said 2-phenyl-indole derivatives are useful in particular as stabilizers of polymers and co-polymers of vinyl chloride.
The invention relates to new compounds of the general formula : ##STR1## wherein X represents a hydrogen or halogen atom, R.sub.1 and R.sub.2, which are the same or different, each represent a hydrogen atom or a methoxy radical and R.sub.3 represents an alkyl or aryl radical, with the proviso that at least one of the substituents R.sub.1 and R.sub.2 is not a hydrogen atom. The compounds of formula I are useful for preparing stabilizers for thermoplastic resins.