将对甲氧基苯硼酸和原料，三乙胺，乙酸铜在二氯甲烷中反应即可。最后用盐酸洗。Under a nitrogen atmosphere, (L)-N-(t-butyloxycarbonyl)-O-(p-toluenesulfonyl)tyrosine methyl ester (0.45 g, 1.0 mmol), cesium carbonate (0.65 g, 2.0 mmol), tricyclohexylphosphine (0.059 g, 0.2 mmol) and bis(1,5-cyclooctadiene)nickel (0.028 g, 0.1 mmol) were mixed in dioxane (1 ml) which had been previously mixed with a mixture (0.28 g, 2.0 mmol) of 4-methylphenylboronic acid and a boroxine ring compound thereof and water (0.03 g). The reaction mixture was heated to 70.degree. C. and then stirred at the same temperature for 3 hrs. After the reaction was completed, the mixture was left to cool to room temperature and insoluble substances were filtered off. The filtrate was subjected to column chromatography purification to obtain (L)-N-(t-butyloxycarbonyl)-4-(4-methylphenyl)phenylalanine methyl ester (0.33 g, yield 89%) as white crystals.