An intermediate, 1-(4’-methoxyethoxyl phenyl) piperazine (Ⅲ), was synthesized from 1-(4’-hydroxylphenyl)-piperazinyl ethanone (Ⅰ) via etherification and hydrolysis. Another intermediate (Ⅶ) with a nitrogen condensed ring was prepared from methyl furan-2-carboxylate (Ⅳ) by acylation, ring-closure and halogenation. Finally, Preladenant was prepared from the both intermediates by condensation reaction. FT-IR, 1HNMR and ESI-MS were employed to characterize these intermediates and the aim compound. Through common synthetic method, the yields of these 6 steps are 99.0%, 95.4%, 98.0%, 78.9%, 86.9%（calculated by Cl） and 52.5% , respectively. To obtain higher total yield, ultrasonic was used in the last condensation reaction. The results showed that the condensation yield reached 85.4% when the reaction conditions were as follows the ultrasonic power (150W), the molar ration of intermediate 2 to 5 (1.2 : 1), soluent (DMSO), acid-bonding agent (Na2CO3), reaction temperature (90 ℃) and reaction time (1.5 h). The yield of the condensation is greatly increased by ultrasonic method.