目的 :合成 6 氟 L多巴 (FDOPA)。方法 :以硝基藜芦醛为原料 ,经亲核取代、还原碘化、手性相转移催化烷基化、水解及HPLC纯化等步骤制备FDOPA ,用手性流动相结合反相C18柱的HPLC法测定其对映纯度。结果 :合成FDOPA总反应时间 (不包括催化剂的合成时间 )少于 90min ,总产率约为 33 % ,对映纯度大于 95 %。结论 :手性相转移催化烷基化法可以高选择性地合成FDOPA。本研究为 6 [18F] L 多巴及其它 [18F]芳香氨基酸的放射化学合成及其对映纯度的测定提供了可靠的技术 OBJECTIVE: To synthesize 6-fluoro-L dopa (FDOPA). METHODS: FDOPA was prepared from nitro-veratrumraldehyde via nucleophilic substitution, reductive iodination, chiral phase transfer catalysis alkylation, hydrolysis and HPLC purification. The mobile phase was coupled to a reversed-phase C18 column by HPLC Determination of its enantiomeric purity. Results: The total FDOPA reaction time (excluding catalyst synthesis time) was less than 90 min, the total yield was about 33% and the enantiomeric purity was greater than 95%. Conclusion: The chiral phase transfer catalysis alkylation method can synthesize FDOPA with high selectivity. The present study provides a reliable technique for the radiochemical synthesis of 6 [18F] L-dopa and other [18F] aromatic amino acids and the determination of their enantiomeric purity