4-Fluorobenzoylformic acid (1) was prepared by oxidation reaction of 4-fluoroacetophenone with selenium dioxide .Cyclization of 1 with semicarbazide hydrochloride under alkaline conditions gave 5-( 4-fluorophenyl )-6-aza uracil ( 2 ) .5-( 4-fluorophenyl )-6-aza-2′, 3′, 5′-tribenzoyl-uridine ( 3 ) was obtained by the reaction of 2 with 1-O-acetyl-2 ,3 ,5-tri-O-benzoyl-β-D-ribofuranose in anhydrous aceto-nitrile.A novel fluorescent nucleoside probe, 5-(4-fluorophenyl)-6-aza uridine(4), was synthesized by hydrolysis of 3 in methanol.The structure was characterized by 1H NMR, 13C NMR and MS(ESI). In addition , the properties of 4 were also investigated .The results showed that the quantum yield of 4 was up to 0.81 in water and it was very sensitive to environmental polarity .A study of the recognition effect of 4 for different metal cations was carried out .The result indicated that 4 exhibited good selec-tivity toward Pd2+in the range of 5.0 ×10 -7 ~5.0 ×10 -6 mol· L-1 .%4-氟苯乙酮经二氧化硒氧化得到4-氟苯甲酰甲酸(1);1与盐酸氨基脲在碱性条件下经环合反应制得5-(4-氟苯基)-6-氮杂嘧啶(2);2与1-乙酰氧基-2,3,5-三苯甲酰氧基-1-β-D-呋喃核糖在无水乙腈中反应得2′,3′,5′-三苯甲酰氧基-5-(4-氟苯基)-6-氮杂尿苷(3);3在甲醇中水解合成了一种新型荧光核苷探针——5-(4-氟苯基)-6-氮杂尿苷(4),其结构经1H NMR,13C NMR和MS(ESI)表征.并研究了4的性能.结果表明:4在水中的量子产率高达0.81,对极性变化敏感;4可选择性识别Pd2+,在5.0×10-7~5.0×10-6 mol·L-1能定量检测Pd2+.
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