通过迈克尔加成环化反应的α-叠氮基苯并随后进行维蒂希反应,制取2,4,5-三取代的1 H-咪唑和高度取代的吡咯并[1,2- c ]咪唑的新合成策略
摘要:
描述了用于制备高度官能化的1 H-咪唑和5 H-吡咯并[1,2- c ]咪唑的有效而简便的方法。在纯净的条件下加热α-叠氮hal烷和N,N,N',N'-四甲基胍的混合物,通过迈克尔加成环化以相应的产率得到相应的2,4,5-三取代的1 H-咪唑。随后,在二氯甲烷中在三苯膦存在下,将制得的1 H-咪唑与炔属酯进行加成-Wittig反应,以高收率提供5 H-吡咯并[1,2- c ]咪唑。
An efficient, one-pot and three-component synthesis of a new series of 2-acyl-3,4,6-triaryl-1,4-dihydropyrazines is described. This two-step strategy involves treatment of phenacyl bromides and anilines to give the nucleophilic substitution intermediate followed by Michael-addition-cyclization to α-azidochalcones to afford the title compounds in high yields.
Hydrazine-1-carbonitriles: new synthesis approach to and reactions with carbonyl compounds
作者:Boris V. Paponov、Oleg V. Shihkin、Svetlana V. Shishkina、Yulia A. Kovach、Sergey A. Kravchenko、Andrey O. Doroshenko
DOI:10.1007/s00706-009-0184-9
日期:2009.11
AbstractA series of 1-(pyrimidin-2-yl)hydrazine-1-carbonitriles was synthesized by base-catalyzed condensation of 3,4-diamino-1,2,4-triazole hydrobromide with several 1,3-dinucleophilic compounds. These final products were formed by ring opening of the 1,2,4-triazolium ring via intermediate 3-amino[1,2,4]triazolo[1,5-a]pyrimidinium bromides. Graphical Abstract
摘要通过3,4-二氨基-1,2,4-三唑氢溴酸盐与几种1,3-二亲核化合物的碱催化缩合反应,合成了一系列1-(嘧啶-2-基)肼-1-腈。这些最终产物是通过中间体3-氨基[1,2,4]三唑并[1,5- a ]嘧啶溴化物开环1,2,4-三唑鎓环而形成的。 图形概要
Tautomerism of diazepines fused with pyrimidine rings
作者:Valentin A. Chebanov、Sergey M. Desenko、Oleg V. Shishkin、Nadezhda N. Kolos、Sergey A. Komykhov、Valery D. Orlov、Herbert Meier
DOI:10.1002/jhet.5570400102
日期:2003.1
The tautomerism of 1,4-diazepines fused with pyrimidine rings was studied by means of nmr spec-troscopy, X-ray analysis and quantum chemical calculations. It was found that in the case of 6,8-diphenyl-pyrimido[4,5-b][1,4]diazepin-4-ols (7a - e) the enamine form is more stable than the diimine form. This result is rationalized with the electron-withdrawing effect of the 4-hydroxypyrimidine ring and
通过核磁共振光谱,X射线分析和量子化学计算研究了与嘧啶环稠合的1,4-二氮杂的互变异构现象。发现在6,8-二苯基-嘧啶[4,5- b ] [1,4]二氮杂-4-醇(7a-e)的情况下,烯胺形式比二亚胺形式更稳定。该结果通过4-羟基嘧啶环的吸电子作用和分子间氢键的形成得以合理化。与7a-e相比,6,8-二芳基-2,3,4,7-四氢-1,3-二甲基-1 H-嘧啶基[4,5- b ] [1,4]二氮杂-2,二亚胺形式存在4-二酮(9a,c,f)。
Reactions of 5,6-diamino-1,3-dimethyluracil with halogen derivatives of chalcones
作者:V. D. Orlov、N. N. Kolos、M. Tu�ni、E. Yu. Yur'eva、S. M. Ivkov
DOI:10.1007/bf00474494
日期:1992.7
ANTIMALARIALS. α,β-DIMORPHOLINYL KETONES AND RELATED COMPOUNDS<sup>1, 2</sup>
作者:ROBERT E. LUTZ、TELLIS A. MARTIN、JOHN F. CODINGTON、T. M. AMACKER、R. K. ALLISON、N. H. LEAKE、R. J. ROWLETT、J. D. SMITH、J. W. WILSON