首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   66篇
  免费   1篇
化学   65篇
晶体学   2篇
  2019年   1篇
  2017年   1篇
  2016年   1篇
  2015年   4篇
  2014年   5篇
  2013年   12篇
  2012年   6篇
  2011年   7篇
  2010年   6篇
  2009年   6篇
  2008年   6篇
  2007年   5篇
  2006年   2篇
  2005年   3篇
  2004年   2篇
排序方式: 共有67条查询结果,搜索用时 15 毫秒
1.
Interaction of 3-amino-5-methylpyrazole, 3-amino-5-methylthio-, and 3,5-diamino-1,2,4-triazole with Meldrum’s acid, acetone, ethyl methyl ketone, and cyclohexanone leads to alkyl-substituted pyrazolo[3,4-b]pyridin-6-ones and 1,2,4-triazolo[1,5-a]pyrimidin-7-ones respectively. The structure of 5,5-dimethyl-2-methylthio-4,5,6,7-tetrahydro-1,2,4-triazolo[1,5-a]pyrimidin-7-one was demonstrated by an X-ray structural investigation. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 595–601, April, 2007.  相似文献   
2.
Acylation of 3-ethoxycarbonyl-2,6-dimethyl-5-pyridinecarboxylic acid hydrazide and 2,6-dimethyl-3,5-pyridinedicarboxylic acid dihydrazide using aromatic acid chlorides gave the corresponding N-aroyl hydrazides. It was found that the hydrazinolysis of 3-ethoxycarbonyl-2,6-dimethyl-5-pyridinedicarboxylic acid N-aroyl hydrazides occurred not at the ester group but as a rehydrazinolysis reaction at the dihydrazide fragment. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1834–1845, December, 2005.  相似文献   
3.
Interaction of 2-aminothiophenol with β-aroylacrylic acids and their dibromo derivatives led to 2-(2-aryl-2-oxoethyl)-4H-benzo-1,4-thiazin-3-ones. The structure of synthesized compounds was confirmed by IR, 1H, and 13C NMR spectra and X-ray analysis.  相似文献   
4.
The interaction of 2-chloroquinoline-3-carbaldehydes with 1H-benzimidazol-2-ylacetonitriles and 1-benzyl-1H-imidazol-2-ylacetonitrile has been studied. It was shown that products of condensation at the methylene group are formed under mild conditions. Carrying out the reaction under more forcing conditions leads to an intramolecular nucleophilic substitution of the chlorine atom and the formation of cyclic ionic compounds (in the case of N-substituted hetarylacetonitriles), which are subsequently dealkylated.  相似文献   
5.
6.
Model complexes of hexaethynylhexamethoxy[6]pericyclyne (HM6P) molecules, with or without dichloromethane (DCM) guests, have been calculated at the M05-2X/6-311G(d,p) DFT level. Analysis of nonbonding interactions shows that the cohesion of the supramolecular tubular assemblies previously observed in the crystal state, relies mainly on C-H···O hydrogen bonds between axial ethynyl and equatorial methoxy substituents of stacked HM6P C(18) macrocycles in a cyclohexane-like chair conformation. The intrinsic binding energy of one HM6P molecule with two neighbors is calculated to be more than 40 kcal mol(-1). The inner channel of the stacks (of ca. 8 ? diameter) are suitable for hosting DCM molecules. Using the Atoms In Molecules (AIM) theory, the interaction between DCM molecules and surrounding triple bonds is analyzed in terms of σ-hole-directed C-Cl···π halogen bonds. A σ-hole-directed Cl···Cl interaction between two chlorine atoms of different DCM molecules is also evidenced.  相似文献   
7.
8.
A convenient synthesis of isothiochromen-4-one 2,2-dioxide was carried out via cyclisation of o-cyanobenzyl thioacetate by a Thorpe reaction. The reactions of isothiochromen-4-one 2,2-dioxide with nitrogen-containing nucleophilic reagents have been investigated.  相似文献   
9.
X-ray diffraction analysis of 1-ethyl-4-hydroxy-N-(6-hydroxybenzothiazolyl-2)-2-oxo-1,2-dihydroquinoline-3-carboxamide has been performed. In crystal, the compound exists as a 2-oxo-4-hydroxy tautomer.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号