Specific features of the reactions of quinazoline and its 4-hydroxy and 4-chloro substituted derivatives with C-nucleophiles
摘要:
Reactions of quinazoline 1 with indole, pyrogallol and 1-phenyl-3-methylpyrazol-5-one in the presence of acid led to C-4 adducts 2, 3 and 5. Adduct 4 is formed by heating I with 1,3-dimethylbarbituric acid without acid catalysis. 1-Phenyl-3-methylpyrazol-5-one reacts with 1 without acid catalysis to form dipyrazolylmethane 6. 4-Chloroquinazoline 8 reacts with 1-phenyl-3-methylpyrazol-5-one to form 4-(1-phenyl-3-methyl-5-oxopyrazol-4-yl) quinazoline 9 and dipyrazolylmethane 6. Heating 8 with 2-methylindole leads to the formation of 4-(2-methylindol-3-yl) quinazoline 10 and tris(2-methylindol-3-yl)methane 11. (C) 2009 Elsevier Ltd. All rights reserved.
Straightforward synthesis of diverse dipyrazolylmethane derivatives and their application for fluorescence sensing of Cu<sup>2+</sup> ions
作者:Kaliappan Kaliraj、Likai Xia、Thomas Nesakumar Jebakumar Immanuel Edison、Yong Rok Lee
DOI:10.1039/c6ra10530k
日期:——
A variety of dipyrazolylmethane derivatives were synthesized from the reactions of readily available β-keto esters with arylhydrazine hydrochlorides and DMF in the presence of p-toluenesulfonicacid (p-TsOH). This methodology provides a concise and practical one-pot route for the construction of diverse dipyrazolylmethane derivatives in good yield. As an application, the synthesized nitro-substituted
New Synthetic Potential of Pteridine Derivatives: Direct Substitution of H in 1,3-Dimethyllumazine During Reaction with C-Nucleophiles
作者:Yu. A. Azev、O. S. Ermakova、A. M. Gibor、M. A. Ezhikova、M. I. Kodess、O. N. Chupakhin
DOI:10.1007/s10600-016-1650-3
日期:2016.3
substitution of H in unsubstituted 1,3-dimethyllumazine was reported for the reaction with alkylamines in the presence of oxidizers to give 7-substituted 1,3-dimethyl-2,4-dioxopyrimido-[4,5-b]pyrazine derivatives [4]. The C-6 atom of 1,3-dimethyllumazine was alkoxylated regioselectively during the reaction with N-bromosuccinimide in alcohols [5]. Examples of direct functionalization of C–H bonds using C-nucleophiles
Friedlander synthesis of novel benzopyranopyridines in the presence of chitosan as heterogeneous, efficient and biodegradable catalyst under solvent-free conditions
作者:Zeba N. Siddiqui、Kulsum Khan
DOI:10.1039/c3nj00069a
日期:——
Efficient synthesis of benzopyrano[4,3-b]pyridine derivatives was achieved from 4-amino-3-formylcoumarin and different active methylene compounds undersolvent-free thermal heating at 80 °C via Friedlander condensation in the presence of chitosan as heterogeneous, basic green catalyst. The present methodology is a novel green approach to benzopyranopyridine. It offers several advantages such as shorter
高效合成苯并吡喃并[4,3- b ]吡啶衍生物4-氨基-3-甲酰基香豆素在不存在溶剂的情况下,在80°C下通过Friedlander缩合在无溶剂的条件下进行加热加热,得到不同的活性亚甲基化合物壳聚糖作为非均质碱性绿色催化剂。本方法学是一种新颖的绿色方法苯并吡喃吡啶。它具有许多优点,例如反应时间短,反应条件温和,操作程序简单,使用可回收和可生物降解的催化剂。
New investigation of Vilsmeier-type reaction using pyrazolones with various amides
作者:Yu-Ying Huang、Kimiyoshi Kaneko、Hiroyuki Takayama、Masayuki Kimura、Fung Fuh Wong
DOI:10.1016/j.tetlet.2011.05.055
日期:2011.7
New investigation of Vilsmeier-type reaction was evaluated to realize the solvent effect by using pyrazolones to react with various of amides, including formamide, N-methylformamide, N-propylformamide, N-tert-butylformamide, N,N-dimethylformamide (DMF), N,N-diethylformamide (DEF), N,N-dipropylformamide (DPF), N,N-diisopropylformamide, N,N-dibutylformamide, piperidine-l-carbaldehyde, and pyrrolidine-l-carbaldehyde, in the presence of phosphorous oxychloride POCl3. The unexpected resulting products were observed in this work according to the difference chemoseletivities of substituted amides. The plausible reactive pathways were proposed to explain the experimental result. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.