Study on the Synthetic Method of d-Naproxen's Intermediate 2-(6'-methoxy-2'-naphthyl) Propenoic Acid

Ethyl [2 hydroxy 2 (6' methoxy 2' naphthyl)] propionate (Ⅲ) was synthesized by the reaction of ethyl pyruvate (Ⅱ) and 2 methoxynaphthalene (Ⅰ) in the presence of the catalyst AlCl\-3.The optimum reaction conditions were:mole ratio of Ⅱ∶Ⅰ=1 2∶1,reaction temperature 0-5 ℃ and reaction time 1 5 h.Ⅲ was hydrolyzed in the presence of alkali for 32 h to give 2 hydroxy 2 (6' methoxy 2' naphthyl) propionic acid (Ⅳ).The yield of above two reactions was 74 8%.Ⅳ was dehydrated in the presence of acid to give 84.6% 2 (6' methoxy 2' naphthyl) propenoic acid (Ⅴ).Ⅴ was asymmetrically hydrogenated to prepare d naproxen (Ⅵ).