5-取代-1-乙酰基-2-硫代海因衍生物的微波快速合成

微波辐射下，硫氰酸铵与a-氨基酸在乙酸酐和冰乙酸的混合溶剂中反应，快速合成了9种5-取代-1-乙酰基-2-硫代海因衍生物. 探讨了微波反应时间、微波反应温度、硫氰酸铵用量及乙酸酐用量对产率的影响，得到了最佳反应条件：a-氨基酸用量10 mmol，硫氰酸铵用量16 mmol，乙酸酐用量9 mL(冰乙酸用量1 mL)，微波反应温度100℃，微波反应时间2 min. 与常规加热法相比，反应时间由30 min缩短到2 min，产率由55.2%~79.5%提高到85.0%~93.0%. 产物结构经1H-NMR, IR和元素分析验证.

Rapid Synthesis of 5-Substituted-1-acetyl-2-thiohydantoin Derivatives under Microwave Irradiation

Nine 5-substituted-1-acetyl-2-thiohydantoin derivatives were rapidly synthesized by the reaction of ammonium thiocyanate and a-amino acids using acetic anhydride and acetic acid as mixed solvent under microwave irradiation. The effects of microwave reaction time, microwave reaction temperature, ammonium thiocyanate dosage and acetic anhydride dosage on their yields were examined. The optimum reaction conditions were obtained as follows: 10 mmol a-amino acid, 16 mmol ammonium thiocyanate, 9 mL acetic anhydride (1 mL acetic acid), 100℃, 2 min. Compared with conventional heating method, the reaction time was shortened from 30 to 2 min, and the yield was raised from 55.2%~79.5% to 85.0%~93.0%. The structures of all products were characterized by 1H-NMR, IR spectra and elemental analysis.