吡唑嘌呤席夫碱的合成

以苯肼、盐酸氨基脲为起始物,经缩合、Vilsmeier-Haak 试剂(DMF/POCl_3)环化、再缩合消除合成了2种吡唑嘌呤席夫碱:1,2-二甲基-2-{2-{6-氯-2[(3-苯基-1H-吡唑-4基)亚甲氨基]-9H-嘌呤-9-基}乙基}丙二酸和二甲基-2-{2-{6-氯-2[(5-氯-3甲基-1-苯基-1H-吡唑-4基)亚甲氨基]-9H-嘌呤-9-基}乙基}丙二酸。其中吡唑酮环化反应的最佳反应条件为:反应温度70℃,反应时间5 h,收率在80%以上。目标产物总收率分别为79.7%和71.8%,通过熔点测定、红外光谱、核磁共振光谱对目标物化学结构进行了表征。

SYNTHESIS OF PYRAZOLE PURINE SCHIFF BASE

Two kinds of pyrazole purine shift base,(E)-dimethyl 2-(2-(6-chloro-2-((3-phenyl-1H- pyrazol-4-yl)methyleneamino)-9 H-purin-9-yl)ethyl)malonate and(E)-dimethyl 2-(2-(6-chloro-2-((5- chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)methyleneamino)-9 H-purin-9-yl)ethyl)malonate were syn- thesized for the first time by condensation,cyclization with Vilsmeier-Haak reagent,and then con- densed elimination using phenyl hydrazine with semicarbazide hydrochloride as raw materials.The op- timum cyclization reaction conditions of the pyrazolone are:reaction temperature 70 ℃ and reaction time 5 h.The yield of each step is much higher than 80 %,and the total yields for the first and second steps are 79.7% and 71.8%,respectively.In this article we provided a convenient and high yield method to synthesize the pyrazole purine shift base.Through melting point test,IR and ~1H NMR, the structures and formula of the target compounds were characterized