2.27 g (10.6 mM) of 4-hydroxybiphenyl-4'-carboxylic acid, 3.71 g (21.3 mM) of butyldimethyl-3-hydroxypropylsilane, 0.25 g (1.31 mM) of p-toluenesulfonic acid and 30 ml of xylene were mixed and heat-refluxed for 8 hours under stirring. After the reaction, the reaction mixture was cooled, followed by distilling-off of xylene under reduced pressure. The resultant residue was dissolved in ethyl acetate and washed with water, followed by drying with anhydrous magnesium sulfate. The magnesium sulfate in the resultant mixture was filtered off and the filtrate was condensed into a solid under reduced pressure, followed by purification by silica gel column chromatography (eluent: toluene) to obtain 1.87 g of 3-butyldimethyl-silylpropyl 4'-hydroxybiphenyl-4-carboxylic acid (Yield; 47.6 %).
