Four different no carrier added (n.c.a.) 4-[18F]fluorophenylurea derivatives are synthesized as model compounds via two alternative routes. In both cases carbamate-4-nitrophenylesters are used as intermediates. Either n.c.a. 4-[18F]fluoroaniline reacts with carbamates of several amines, or the carbamate of n.c.a. 4-[18F]fluoroaniline is formed at first and an amine is added subsequently to yield the urea derivative. The choice of the appropriate way of reaction depends on the possibilities of precursor synthesis. The radiochemical yields reach up to 80% after 50 min of synthesis time while no radiochemical by-products can be determined. These high yields were possible due to an optimized preparation of n.c.a. 4-[18F]fluoroaniline with a radiochemical yield of up to 90%. From the various ways of its radiosynthesis, the substitution with n.c.a. [18F]fluoride on dinitrobenzene is chosen, using phosphorous acid and palladium black for reduction of the second nitro group. Copyright © 2006 John Wiley & Sons, Ltd.
合成了四种不同的无载体添加(n.c.a.)4-[18F]
氟苯基
尿酸酯衍
生物作为模型化合物,采用了两种不同的合成路径。在这两种情况下,
碳酸酯-4-
硝基苯酯被用作中间体。无载体添加的4-[18F]
氟苯胺与几种胺的
碳酸酯反应,或者先形成无载体添加的4-[18F]
氟苯胺的
碳酸酯,再随后添加胺以生成
尿酸酯衍
生物。选择适当的反应路径取决于前体合成的可能性。
合成时间为50分钟时,放射
化学产率可达80%,而未检测到放射
化学副产物。这些高产率的获得归功于优化的无载体添加4-[18F]
氟苯胺的制备,其放射
化学产率高达90%。在多种放射合成方式中,选择了在
二硝基苯上用无载体[18F]
氟化物进行取代,并采用
磷酸和黑色
铂进行第二个硝基的还原。 版权所有 © 2006 John Wiley & Sons, Ltd.