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41.
通过6-氨基嘧啶、取代苯甲醛与丙二腈的三组分反应合成了4种吡啶并[2,3-d]嘧啶受体分子,利用紫外-可见吸收光谱考察了其与F-,Cl-,Br-,AcO-,4HSO-,2 4H PO-等阴离子的作用.结果表明该类受体分子与阴离子形成氢键配合物,导致吡啶并[2,3-d]嘧啶受体的光谱发生变化.测定了配合物的结合比和稳定常数,发现受体化合物对AcO-离子具有良好的选择性,对其它多种阴离子无影响.Job曲线表明受体分子与阴离子间形成1∶1型的配合物.1H NMR滴定进一步证实了氢键作用的存在及参与类型.  相似文献   
42.
利用多组分反应方法,合成了一种螺环结构的2′,7′-二氨基-5-甲基-2,4′-二氧代-4′,8′-二氢-3’H-螺[吲哚啉-3,5′-吡啶[2,3-d]嘧啶]-6′-腈化合物4,并对该化合物进行了红外光谱、核磁共振氢谱、元素分析以及X-射线单晶衍射表征.单晶衍射结果表明:该晶体属于三斜晶系,空间群P-1,晶体参数为a=1.308 1nm,b=1.316 3nm,c=1.454 2nm,α=71.668(1)°,β=78.074(2)°,γ=66.475(1)°.在每个晶胞结构单元中含有一对对映异构体分子,分子中通过螺碳原子相连的吲哚环和二氢吡啶环处于几乎垂直构型,其二面角为89.15(2)°;稠合的二氢吡啶环和嘧啶环几乎共平面,其二面角为0.93(2)°.  相似文献   
43.
Pyriminostrobin, a new acaricide, was discovered in our previous studies. Because introducing fluorine into organic compounds can increase bioactivity, pyriminostrobin was modified as a series of strobilurin-pyrimidine derivatives for biological screening. The compounds were characterized by 1H NMR, MS and elemental analysis. Preliminary bioassays demonstrated that compounds 7e and 7i exhibited significant control against Tetranychus cinnabarinus (Boisd.) at 0.625 mg L^-1, and their acaricidal potencies were higher than pyriminostrobin in a greenhouse. The relationship between structure and acaricidal activity was also studied.  相似文献   
44.
An efficient synthesis of Biginelli-type compounds using potassium phthalimide as a green, mild, and commercially available organocatalyst in a one-pot, multi-component cyclocondensation reaction of cyclopentanone, aldehydes, and urea/thiourea is reported. The present methodology is a green approach to access 4-aryl-7-(aryImethylene)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-ones/thiones. It offers several merits such as simple operational procedures, no use of hazardous organic solvents, and cheap and environmentally friendly solid basic catalyst.  相似文献   
45.
With the increase of herbicide-resistant weeds, novel, more selective and even more potent herbicides to control weeds are needed. In this paper, a series of N-fluorinated phenyl-N'-pyrimidyl urea derivatives were synthesized and screened for their herbicidal activities against Amaranthus retroflexus (AR) and Setaria viridis ( SV). Compound 2S (N-(3-trifluoromethylphenyl)-N'-(2-amino-4-chloro-6-methylpyr- imidyl) urea) exhibited marked herbicidal activity against SV(IC50 =11.67 mg/L) and is more potent than bensulfuron (IC50= 27.45 mg/L), a commercially available herbicide. A statistically significant CoMFA model with high prediction abilities (q2 = 0.869, r2 = 0.989) was obtained.  相似文献   
46.
黄统辉  陈华  陈杰  张爱东 《结构化学》2014,33(10):1455-1459
Two 5-pyrimidinyl-1,2,4-oxadiazoles were synthesized through two different routes and their structures were characterized by single-crystal X-ray diffraction, NMR and MS. Compound 3, 5-(2-chloro-4-methyl-6-phenylpyrimidin-5-yl)-3-phenyl-1,2,4-oxadiazole, crystallizes in orthorhombic, space group Pbca with a = 19.1575(11), b = 8.2115(5), c = 21.2035(12), V = 3335.6(3)3 and Z = 4. Compound 6, 5-(2,6-dichloropyrimidin-4-yl)-3-phenyl-1,2,4-oxadiazole, crystallizes in monoclinic space group Pn with a = 8.4275(13), b = 5.4088(8), c = 13.493(2), β = 99.768(3)o, V = 4658.6(6)3 and Z = 8. Preliminary bioassay indicated that the two title compounds had good herbicidal activities.  相似文献   
47.
An efficient and environmentally friendly procedure for the one-pot synthesis of 13-acetyl-9-methyl-11-oxo-8-oxa-10,12-diazatricyclo7.3.1.02,7trideca-2,4,6-triene from salicylaldehyde, acetylacetone and urea via Biginelli condensation and intramolecular Michael-addition by using magnesium bromide as an inexpensive and easily available catalyst in a solvent-free condition is described. The structural elucidation of the product is reported by 1H- and 13C-NMR spectra. The product can also be identified by its EI TOF mass spectrometry based on the molecular ion at m/s 246(10%) and on the fragment ions in which two nitrogen atoms are remained. Three kinds of characteristic fragmentation pathways from the molecular ion were observed. One is the loss of the OH radical to form the dihydropyrimidinone cation at m/z 229(48%), followed by elimination of a molecular methane forming the pyrimidinone cation at m/z 213(27%). The second is the cleavage of the C6H4OH radical, and the formation of the dihydropyrimidinone cation at m/z 153(24%). The third one is the loss of MeC=O radical to afford the oxygen-bridged fragment ion at m/z 203(33%).  相似文献   
48.
利用2-氨基-4,6-二甲氧基嘧啶在干燥条件下与硫氰酸钾、氯甲酸甲酯在乙酸乙酯溶液中反应制得4-(4,6-二甲氧基嘧啶-2-基)-3-硫代脲酸甲酯, 在二甲基甲酰胺溶液中培养出单晶, 通过X射线单晶结构分析法测定分子结构和晶体结构, 晶体属单斜晶系, 空间群为C2/m, 晶胞参数为: a=1.6672(3) nm, b=0.66383(12) nm, c=1.1617(2) nm, β=109.275(2)°, V=1.2136(4) nm3, Dc=1.490 g/cm3, μ=0.281 mm-1, F(000)=568, Z=4, R1=0.0341, wR2=0.1042. 运用Gaussian 03程序, 在6-311G的基组水平上, 用HF, MP2以及B3LYP三种计算方法对标题化合物进行了几何全优化, 并对其成键情况及自然键轨道(NBO)进行了分析.  相似文献   
49.
李明  郭维斯  文丽荣  曲波 《结构化学》2006,25(1):108-112
1INTRODUCTION Pyrazolo[1,5-a]pyrimidine derivatives have shown various biological activities in the terms of antibac-terial,antischistosomal and xanthine oxidase inhibi-tors[1~5].The enaminones are highly reactive inter-mediates and have been extensively used as build-ing blocks in organic synthesis especially in the he-terocyclic compounds[6~8].In addition,a great deal of interest has been focused on the synthesis of py-razolo[1,5-a]pyrimidine through versatile enamino-nes because of thei…  相似文献   
50.
以4-氯-5硝基嘧啶(3)为起始物, 经胺解、还原和环合等反应, 构建了新型的多取代嘌呤-8-硫酮(6)结构. 通过化合物6与卤代物的反应, 获得了该杂环的8位巯基衍生物7a-1~7, 7b-1~5和8, 其结构经元素分析, 1H NMR, IR及MS确证. 生物活性测试结果表明,  化合物6和7具有一定的除草和抗烟草花叶病毒活性.  相似文献   
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