NOVELTY - Synthesis of nateglinide involves adding trans-4-isopropyl-cyclohexyl carboxylic acid to phosphorus pentachloride, stirring, evaporating solvent, vacuum-distilling, forming trans-4-isopropyl-cyclohexyl chloride, adding D-phenylalanine into sodium hydroxide solution and acetone, cooling, stirring, dripping trans-4-isopropyl-cyclohexyl methyl chloride, heating, acidifying, stirring, precipitating, filtering, washing with distilled water, drying, forming nateglinide crude product, dissolving crude product with acetone, stirring, cooling, filtering, and washing.    USE - Synthesis of nateglinide (claimed).    ADVANTAGE - The nateglinide is manufactured efficiently and economically with high yield and excellent reliability, by simple method.    DETAILED DESCRIPTION - Synthesis of nateglinide involves mixing solution of 4-isopropyl-toluene, acetic acid, cobalt acetate, stirring in oil bath, heating to 80-85 degrees C under oxygen atmosphere, reacting for 7.5 hours, cooling to room temperature, filtering, evaporating, adjusting pH using sodium hydroxide to less than 10, stirring for 0.5 hours, extracting, separating, washing, filtering, drying, forming 4-isopropyl-benzoic acid crude product, recrystallizing using ethanol, drying to give 4-isopropyl benzoic acid, adding 4-isopropyl-benzoic acid to glacial acetic acid and platinum oxide in autoclave at 25 degrees C under a hydrogen pressure, filtering, evaporating under reduced pressure, dissolving in 4-isopropyl toluene, stirring, heating to 145 degrees C, stirred for 6.5 hours, cooling to 40 degrees C, extracting, separating, cooling, acidifying with concentrated hydrochloric acid, precipitating, filtering, washing with cold water, drying, recrystallizing, forming trans-4-isopropyl-cyclohexyl carboxylic acid, adding trans-4-isopropyl-cyclohexyl carboxylic acid to phosphorus pentachloride, stirring at 40 degrees C for 3 hours, evaporating solvent, vacuum-distilling, forming trans-4-isopropyl-cyclohexyl chloride, adding D-phenylalanine into 2%-sodium hydroxide solution and acetone, cooling, stirring, dripping trans-4-isopropyl-cyclohexyl methyl chloride, heating, acidifying using with hydrochloric acid, stirring, precipitating, filtering, washing with distilled water, drying, forming nateglinide crude product, dissolving crude product with acetone, heating, stirring at room temperature for 24 hours, cooling, filtering, and washing.