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4H-[1]benzopyrano[3,4-c][1,2,5]selenodiazol-4-one has been synthesized by the reaction of 3,4-diaminocoumarin with selenous acid and its reaction with several nucleophiles (alkali, ammonia, amines, hydrazine hydrate) and its nitration have been studied. Using PMR spectroscopy, a comparative kinetic study of the opening of the lactone ring in 6,8-dinitro-4H-[1]benzopyrano[3,4-c][1,2,5]seleno- and thiadiazol-4-ones has been carried out.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 128–133, January, 1991.  相似文献   

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31P solid-state nuclear magnetic resonance (NMR) spectra of 12 metal-containing selenophosphates have been examined to distinguish between the [P(2)Se(6)](4-), [PSe(4)](3-), [P(4)Se(10)](4-), [P(2)Se(7)](4-), and [P(2)Se(9)](4-) anions. There is a general correlation between the chemical shifts (CSs) of anions and the presence of a P[bond]P. The [P(2)Se(6)](4-) and [P(4)Se(10)](4-) anions both contain a P[bond]P and resonate between 25 and 95 ppm whereas the [PSe(4)](3-), [P(2)Se(7)](4-), and [P(2)Se(9)](4-) anions do not contain a P[bond]P and resonate between -115 and -30 ppm. The chemical shift anisotropies (CSAs) of compounds containing [PSe(4)](3-) anions are less than 80 ppm, which is significantly smaller than the CSAs of any of the other anions (range: 135-275 ppm). The smaller CSAs of the [PSe(4)](3-) anion are likely due to the unique local tetrahedral symmetry of this anion. Spin-lattice relaxation times (T(1)) have been determined for the solid compounds and vary between 20 and 3000 s. Unlike the CS, T(1) does not appear to correlate with P-P bonding. (31)P NMR is also shown to be a good method for impurity detection and identification in the solid compounds. The results of this study suggest that (31)P NMR will be a useful tool for anion identification and quantitation in high-temperature melts.  相似文献   

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8-[4-[4-(2-Pyrimidinyl)-1-piperaziny]butyl]-8-azaspiro [4,5] decane-7,9-dione hydrochloride (buspirone hydrochloride) was obtained in one pot with a 51.8% overall yield. The key intermediate, 1-(2-pyrimidinyl) piperazine, was synthesized through chlorination and cyclization condensation reaction with diethanolamine as initial material. This modified protocol has the notable advantages of mild reaction condition, convenient operation, and high overall yield.  相似文献   

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Synthesis and single-crystal X-ray structures of mixed triple and double calixarenes 6 and 7, obtained from the base-catalyzed condensation of calix[5]arene 1 with cone pertosylated calix[4]arene 2, are reported. VT-NMR studies on 7 are consistent with a molecular motion arising from the anti-gauche conformational interconversion of its ethylene linkages.  相似文献   

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郑礼康  金明  张敬先  韩世清 《合成化学》2011,19(6):782-784,787
以对甲苯胺和对甲基苯甲酸甲酯为起始原料,经NBS溴化、亲核取代、酸水解和Knoevenagel缩合等6步反应合成了抗细菌生物膜化合物—3-[N-(4-甲基苯基)氨基羰基]-5-[4-(4-甲酸基苯甲氧基)苯亚甲基]-2,4-噻唑烷二酮,总收率57.3%,其结构经1H NMR,ESI-MS和元素分析确证.  相似文献   

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Calculations on the structures of dimers of all-metal aromatic and anti-aromatic molecules such as (Al4(2-)) and (Al4(4-)) reveal that, unlike their organic counterparts such as benzene and cyclobutadiene which form pi-stacked complexes, these molecules form new clusters with no reminiscence of the original units. These clusters have a very large binding energy and can be further stabilized through charge-balance by counterions and solvents.  相似文献   

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《Tetrahedron: Asymmetry》2005,16(16):2778-2783
The enantioselective microbial reduction of 6-oxo-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione 1 to either of the corresponding (R)- or (S)-6-hydroxy-8-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-diones 2 and 3 is described.  相似文献   

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以乙睛和乙醇为原料经2步反应合成了2,4,6-三甲基均三嗪(1);以对硝基甲苯和N-乙基苯胺为原料经3步反应合成了4-[4-[N-乙基-N-(2-羟乙基)]氨基苯偶氮基]苯甲醛(4);1与4在氢氧化钾的作用下经羟醛缩合合成了偶氮型八极分子2,4,6-三[4-[4-[N-乙基-N-(2-羟乙基)]氨基苯偶氮基]苯乙烯基]...  相似文献   

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4-[2-cyclopentenyl]-3-hydroxy [1] bonzopyran-2-one(3) was cyclised to the bicyclie coumar in-1,3-ethano-2-bromo-1,2-dihydro-3H-pyrano [2,3-c] [1] benzopyran-5-one (6) by a sequence of reactions viz. acetylation of 3, addition of bromine to cyclopenteny double bond and treating the resulting acetyldibromo compound (5) with 4% alcoholic KOH, Cyclisation of compound (3) with mercuric acetate in methanol gave condensed furan derivative 7 which on reductive demercuration with zinc borohydride in dimethoxyethane gave the 1,3-propano-1,2-dihydrofuro [2,3-c] [1] benzopyran-4-one, 8. Cyclisation of compound 2 with come. H2SO4 furnished a mixture of bicyclic derivative 9 ad furo coumarin derivative 8.  相似文献   

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