Department of Chemistry, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan.
Nat Prod Res. 2010 Mar;24(4):315-25. doi: 10.1080/14786410802435935.
Semicarbazides, besides possessing medicinal properties, also find wide applications in agriculture and industry. We report in this article the synthesis of the four 1,4-disubstituted semicarbazides: 1-cinnamoyl-4-phenyl semicarbazide (1), 1-oleyl-4-phenyl semicarbazides (2), 1,1',1''-tricitryl-4,4',4''-triphenyl semicarbazide (3) and 1-benzoyl-4-phenyl semicarbazide (4), by the condensation of four different hydrazides: cinnamic acid hydrazide (5), oleic acid hydrazide (6), citric acid hydrazide (7) and benzoic acid hydrazide (8). The acid hydrazides were prepared by the condensation of four different acids with phenyl isocyanate. The semicarbazides were also subjected to acid catalysed intramolecular cyclisation. The cyclisation of (1) and (2) afforded substituted 1,3,4-oxadizoles: 2-cinnamoyl-5-aminophenyl 1,3,4-oxadizoles (9) and 2-oleyl-5-aminophenl 1,3,4-oxadizoles (10), respectively, in high yield, while no cyclisation occurred in the cases of (3) and (4). The products in each case have been identified on the basis of melting points and IR spectral studies.
氨基脲除了具有药用性能外,在农业和工业中也有广泛的应用。本文报道了通过缩合四种不同的酰肼:肉桂酸酰肼(5)、油酸酰肼(6)、柠檬酸酰肼(7)和苯甲酰肼(8),合成了四种 1,4-二取代氨基脲:1-肉桂酰基-4-苯基氨基脲(1)、1-油酰基-4-苯基氨基脲(2)、1,1',1''-三(三硝基乙酰基)-4,4',4''-三苯基氨基脲(3)和 1-苯甲酰基-4-苯基氨基脲(4)。这些酸酰肼是通过四种不同的酸与异氰酸苯酯缩合而成的。氨基脲也进行了酸催化的分子内环化反应。(1)和(2)的环化反应分别得到取代的 1,3,4-恶二唑:2-肉桂酰基-5-氨基苯基 1,3,4-恶二唑(9)和 2-油酰基-5-氨基苯基 1,3,4-恶二唑(10),产率很高,而(3)和(4)则没有发生环化反应。每种情况下的产物都是根据熔点和红外光谱研究来确定的。