2-(2H-Benzotriazol-2-yl)-6-chloromethyl-4-methyl-phenol (10.0 g, 33 mmol) is suspended in a mixture of 2-ethylhexanoic acid (11.9 g, 82 mmol) and tetrahydrofuran (75 g) and stirred at 70° C. for 30 minutes. Sodium carbonate (10.5 g, 99 mmol) is added. The reaction mixture is stirred at 60° C. for 15 minutes and evaporated to dryness. The residue is dissolved in ethyl acetate and extracted with an aqueous potassium carbonate solution (10%) and brine. The organic layer is dried over sodium sulphate, filtered and evaporated to dryness. The crude product is purified by column chromatography (ethyl acetate/heptane 1:12) to yield 11.2 g of 2-Ethyl-hexanoic acid 3-(2H-benzotriazol-2-yl)-2-hydroxy-5-methyl-benzyl ester.
