微波干法催化环内酰胺N－烷基化反应

微波干法催化环内酰胺Ｎ－烷基化反应王存德，肖东运，张明，田兆斌，张霖（扬州大学工学院扬州２２５００１）关键词微波辐射，环内酰胺，Ｎ－烷基化，卤代烷Ｎ－烷基环内酰胺广泛应用于医药和日用化学品中［１，２］．近年来有关Ｎ－烷基环内酰胺的合成有：碱叔丁醇钾－...     

1—取代氮杂环庚烷—2—酮的合成

1—取代氮杂环庚烷-2-酮类有比较重要的生理活性,如1-十二烷基氮杂环庚烷-2-酮为目前受重视的新型高效、无毒的透皮吸收促进剂。但内酰胺氮上氢原子的酸性很弱,较难发生N-烷基化反应,为提高1-取代内酰胺的合成产率,我们用混合无机碱KOH/K_2CO_3为缚酸剂,聚     

N-alkylation products of substituted imidazoles and dihydropyrimidinediones with dibromoalkanes

The reactions of N-containing heterocycles with dihaloalkanes were studied. All structures were determined by NMR and mass techniques. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 31–34, January, 2007.     

Ionic liquids as novel and recyclable reaction media for N-alkylation of amino-9,10-anthraquinones by trialkyl phosphites

Ionic liquids such as 1,3-dialkylimidazolium bromides make excellent catalysts and solvents for N-alkylation of amino-9,10-anthraquinones in the presence of trialkyl phosphites. For triethyl phosphite, [bpim][Br] gave better results. The ionic liquids are successfully regenerated and reused.     

Synthesis and Crystal Structure of 5-Amino-7-benzylseleno-8-cyano-3-ethoxycarbonyl-4-(2-furyl)-1,2-dimethyl-1,4-dihydro-1,6-naphthyridine

5-Amino-7-benzylseleno-8-cyano-3-ethoxycarbonyl-4-(2-furyl)-1,2-dimethyl-1,4-dihydro-1,6-naphthyridine was obtained by N-alkylation. X-ray crystallography showed the presence of two symmetrically conformers in the crystal.     

Synthesis of New α-Heterocyclic α-Aminophosphonates

α-heterocyclic α-aminophosphonates were obtained in good yields by N-of several nitrogen heterocycles with α-azido-α-aminophosphonate 1. ¹ Elachqar, A., El Hallaoui, A., Roumestant, M. L. and Viallefont, Ph. 1994. Synthetic Comm, 24: 1279 [CSA][Taylor & Francis Online], [Web of Science ®] , [Google Scholar]     

Simultaneous C- and N-Alkylation of 2-Oxo-4,6-diaryl-1,2,3,4-tetrahydropyridine-3-carbonitrile Under Solid–Liquid Phase-Transfer Conditions

The alkylation of 2-oxo-4,6-diaryl-1,2,3,4-tetrahydropyridine-3-carbonitrile 1 has been carried out using different alkyl/arylating agents in solid–liquid phase-transfer catalysis conditions. The aim was to study the effect of steric hindrance offered by the aryl group in the sixth position of the pyridine ring on the ambient N- vs. O-alkylation ratio. Simultaneous C- and N-alkylation was encountered and confirmed by x-ray crystallography. Our study to gain exclusive regiocontrol for simultaneous alkylation was carried out. An alternative route for C?C bond formation was also established by the removal of the cyano functionality.     

N-Phenacyldibromobenzimidazoles—Synthesis Optimization and Evaluation of Their Cytotoxic Activity

Antifungal N-phenacyl derivatives of 4,6- and 5,6-dibromobenzimidazoles are interesting substrates in the synthesis of new antimycotics. Unfortunately, their application is limited by the low synthesis yields and time-consuming separation procedure. In this paper, we present the optimization of the synthesis conditions and purification methods of N-phenacyldibromobenzimidazoles. The reactions were carried out in various base solvent-systems including K₂CO₃, NaH, KOH, t-BuOK, MeONa, NaHCO₃, Et₃N, Cs₂CO₃, DBU, DIPEA, or DABCO as a base, and MeCN, DMF, THF, DMSO, or dioxane as a solvent. The progress of the reaction was monitored using HPLC analysis. The best results were reached when the reactions were carried out in an NaHCO₃–MeCN system at reflux for 24 h. Additionally, the cytotoxic activity of the synthesized compounds against MCF-7 (breast adenocarcinoma), A-549 (lung adenocarcinoma), CCRF-CEM (acute lymphoblastic leukemia), and MRC-5 (normal lung fibroblasts) was evaluated. We observed that the studied cell lines differed in sensitivity to the tested compounds with MCF-7 cells being the most sensitive, while A-549 cells were the least sensitive. Moreover, the cytotoxicity of the tested derivatives towards CCRF-CEM cells increased with the number of chlorine or fluorine substituents. Furthermore, some of the active compounds, i.e., 2-(5,6-dibromo-1H-benzimidazol-1-yl)-1-(3,4-dichlorophenyl)ethanone (4f), 2-(4,6-dibromo-1H-benzimidazol-1-yl)-1-(2,4,6-trichlorophenyl)ethanone (5g), and 2-(4,6-dibromo-1H-benzimidazol-1-yl)-1-(2,4,6-trifluorophenyl)ethanone (5j) demonstrated pro-apoptotic properties against leukemic cells with derivative 5g being the most effective.     

Catalytic One-Pot Reductive Amination of Carboxylic Acids

The broad applications of primary alkyl amines in various fields have spurred extensive interests in synthetic organic chemistry. Recently, the reductive amination of carboxylic acids has become an attractive and practical strategy for synthesizing primary alkyl amines, due to their wide availability and bench stability. However, the inherent stability and higher oxidation state of carboxylic acids render this new strategy with new challenges. This Concept provides a summary of the recent advancements in the reductive aminations of carboxylic acids, specifically focusing on the catalytic tactics, underlying mechanisms, and applications in the synthesis of valuable products.