Yield:188112-41-6 39%

Reaction Conditions:

Stage #1: 4-benzyloxy-3-ethylbenzaldehydewith ammonium peroxydisulfate;formic acid;phosphoric acid;acetic anhydride in water;toluene at 60; for 20 h;
Stage #2: with toluene-4-sulfonic acid in water;toluene at 20; for 9 h;
Stage #3: with sodium hydrogensulfite in water;toluene; for 0.5 h;

Steps:

4.4

Synthesis of 4-benzyloxy-3-ethylphenol; 4-Benzyloxy-3-ethylphenol was synthesized according to the reaction formula given by [Formula 79] in the following manner.. [Show Image] To a reactor were charged 2.50 g (10 mmol) of 4-benzyloxy-3-ethylbenzaldehyde obtained in Step 3, 3.09 g (14 mmol) of ammonium persulfate, 0.96 g (21 mmol) of formic acid, 0.40 g (4.0 mol) of acetic anhydride, and 15 g of toluene, here was added aqueous solution of phosphoric acid dropwise at 60°C, and the mixture was stirred for 20 hours. After the reaction mixture was cooled to ambient temperature, 0.094 g (0.30 mmol) of p-toluenesulfonic acid dissolved in water was added dropwise, and the mixture was stirred for 9 hours. To the reaction mixture, 20 g of saturated aqueous solution of sodium bisulfite was added, and the mixture was stirred for 30 minutes. The organic layer was washed with water, the solvent was evaporated, and the residue was purified by column chromatography (ethyl acetate:hexane = 1:10, SiO₂) to yield the desired product, 4-benzyloxy-3-ethylphenol, as red liquid (0.92 g, Yield: 39%).

References:

EP1813594,2007,A1 Location in patent:Page/Page column 30-31