Patent ID: 7632949

Claim:
A process for the preparation of a stabilizer of formula (I) comprising the step of reacting, by condensation, isophthalic acic dichloride with a sterically hindered amine of formula (II), wherein R 1 is H, C 6 -cycloalkyl or C 1 -C 4 -alkyl, and R 2 is H, C 1 -C 5 -alkyl, or a C 1 -C 10 -alkyloxy-group, wherein the reacting step includes adding the isophthalic acic dichloride to the amine in a solution of at least one organic solvent, water and NaOH at a temperature of 25 to 35° C. to form a reaction mixture, and heating the reaction mixture in an autoclave to a temperature of 90-110° C. at a system pressure of 1.3-1.7 bars, wherein the organic solvent is selected from an aromatic hydrocarbon and an aliphatic alcohol.