1.0 ml (15.0 mmol) of 2-chloroethanol is added to a solution of 3.38 g (10.0 mmol) of 5,7-di-tert-butyl-3-(4-hydroxyphenyl)benzofuran-2-one in 30 ml of 1N sodium hydroxide solution heated to 80° C. The reaction mixture is then maintained at 80° C. for 2 hours, 50 ml of 1N hydrochloric acid are added, stirring is continued for 1 hour, the mixture is cooled, and the product is extracted with dichloromethane. The organic phases are washed with water, combined, dried over sodium sulfate and concentrated on a vacuum rotary evaporator. Crystallization of the residue from 8 ml of ethanol and 2 ml of water gives 2.34 g (61%) of 5,7-di-tert-butyl-3-[4-(2-hydroxyethoxy)phenyl]-benzofuran-2-one m.p. 132°-135° C. (compound (105), Table 1).
