A mixture of 5.5 g (24 mmol) of 2-benzotriazol-2-yl-4-methyl-phenol, 4.7 g (72 mmol) of potassium hydroxide and 100 ml of n-methylpyrrolidone is stirred for 2 hours at room temperature. Then 8.0 g (24 mmol) 2-bromo-1-(3,5-di-tert-butyl-4-hydroxyphenyl)-propan-1-one dissolved in 40 ml of n-methylpyrrolidone is added and stirring is continued at room temperature for 20 hours. After the addition of 50 ml of water and 15 ml 2N hydrochloric acid the precipitated solid is filtered off and recrystallized from ethanol to give 8.9 g (76%) of compound 117; m.p. 161° C.
