苯偶姻单酯无溶剂微波加热合成2-取代-4,5-二芳基咪唑衍生物

以醛为原料,在维生素B1作用下,经安息香缩合反应制得相应的苯偶姻衍生物,进而以此为原料与不同的酰化试剂酯化生成苯偶姻单酯.苯偶姻单酯与醋酸铵附着在固载体酸性氧化铝上,在无溶剂条件下微波加热合成了17种2-取代-4,5-二芳基咪唑,其中7种未见文献报道.该方法具有反应条件温和、反应时间短,且无需有机溶剂,是一种节能环保、易操作的合成方法.另外,所合成化合物的结构通过IR、高分辨质谱和核磁共振谱进行了确认.     

微波辐射下一步合成2-芳基-4，5-二苯基咪唑衍生物

微波辐射下一步合成2-芳基-4;5-二苯基咪唑衍生物;芳基咪唑; 二苯基二（甲）酮; 芳醛; 微波辐射; 合成     

微波辐射无溶剂条件下快速合成2,4,6-三芳基吡啶四氟硼酸盐

在微波辐射无溶剂条件下快速、高产率地合成了2,4,6-三芳基吡啶四氟硼酸盐化合物, 并对其进行核磁共振、红外光谱、元素分析表征. 同时得到了化合物4f的晶体, 对其进行了X单晶射线衍射表征. 结果表明, 该晶体属正交晶系, 空间群Pbca, a＝2.1050(2) nm, b＝1.64360(17) nm, c＝2.9209(3) nm, α＝β＝90.00°, γ＝90.00°, D_c＝1.276 g•cm^－3, V＝10.1057(17) nm^－3, Z＝16.     

微波辐射下水相中一锅法合成多芳基取代1,2-二氮杂(艹卓)衍生物

微波辐射下,以芳香醛和芳香酮为起始原料,由一锅法合成2,4,6-三芳基硫代吡喃盐,然后直接加入水合肼反应,几乎以定量收率仅只生成3,5,7.三芳基-4H-1,2-二氮杂(艹卓)衍生物.该法以水为反应溶剂且中间盐不用分离,具有操作简单、条件温和、产率高、环境友好等优点.产物经元素分析、1H NMR、MS表征了其结构.     

氯化铝催化合成多芳基取代β-氨基酮衍生物

室温条件下,氯化铝可有效催化苯乙酮、芳香醛和芳香胺的Mannich反应.本文报道用三组分"一锅法"合成了一系列多芳基取代β-氨基酮衍生物,并考察了反应条件对产率的影响.产品结构经IR、1HNMR、MS和元素分析进行表征.该方法条件温和,产率较高,操作简单,对环境友好,且催化剂经简单相分离可回收并多次重复使用.     

改性活性炭负载FeCl_3催化一锅法合成多芳基咪唑

制备了一种新型改性活性炭负载氯化铁催化剂(MAC-Fe Cl3),通过红外光谱及等离子体发射光谱进行了表征.在MAC-Fe Cl3催化下,以乙酸铵为氮源,苯偶酰与芳醛以及伯胺作用,一锅法合成了一系列2,4,5-三芳基咪唑和1,2,4,5-四芳基咪唑.催化剂后处理简单,重复使用4次仍保持较高活性.该方法收率较高、对环境友好、操作简单.     

氨基磺酸催化下三组分一锅法无溶剂合成苯并[4,5]咪唑并[1,2-a]嘧啶类衍生物

无溶剂条件下,用氨基磺酸催化芳香醛,2-氨基苯并咪唑和β-二羰基化合物的三组分反应,简单而方便地得到了苯并[4,5]咪唑并[1,2-a]嘧啶类衍生物.该法具有产率高,成本低廉,环境友好,适应性广简捷方便等优点.     

微波促进下4-芳基亚氨基-1,2,4-三唑的合成

无溶剂;无催化剂;微波辐射;取代基-巯基-芳基亚氨基三唑     

无溶剂条件下利用微波促进下的多组分反应对2,6-二芳基-4-苯乙烯基吡啶化合物进行非预期的绿色简易合成

在无溶剂条件下,通过微波促进下的3-芳基丙烯醛肟、1-芳基乙酮及醋酸铵的多组分反应,非预期地实现了2,6-二芳基-4-苯乙烯基吡啶化合物的绿色简易合成。该方法具有环境友好、反应时间短、产率高、成本低、操作简便以及适用范围广等优点。     

新型N-芳基哌嗪取代苯并呋喃衍生物的合成

以5-二甲氨基水杨醛和2-溴-4'-氟苯乙酮为原料,经缩合和取代反应制得中间体6-二乙氨基-2-[4'-(N-哌嗪基)苯甲酰基]苯并呋喃(2);2与卤代烃反应合成了6个新型的N-芳基哌嗪取代苯并呋喃衍生物(4a~4f),收率76%~93%,其结构经1H NMR,13C NMR和HR-MS(ESI-TOF)表征。     

Potassium dihydrogen phosphate catalyzed one-pot synthesis of 2,4,5-triaryl-1H-imidazoles

<正>A simple and efficient method has been developed;benzil/benzoin undergoes smooth condensation with various substituted aldehyde and ammonium acetate in the presence of potassium dihydrogen phosphate(KH_2PO_4) under mild reaction conditions to afford the corresponding trisubstituted imidazole in excellent yields.The method for synthesis of product,the reaction mixture was reflux in ethanol for 40-90 min.The present method is simple,efficient,and cost-effective.     

Solvent-and catalyst-free synthesis of dihydropyrimidinthiones in one-pot under focused microwave irradiation conditions

Fifteen dihydropyrimidinthiones have been synthesized by microwave-assisted Biginelli reactions without any solvent or catalyst. The advantages of this novel protocol include the excellent yield, operational simplicity, short time and the avoidance of the use of organic solvents and catalysts.     

Design and Optimization of Ecofriendly One-Pot Synthesis of 2,4,5-Triaryl-1H-imidazoles by Three-Component Condensation Using Response Surface Methodology

Phase-transfer-catalyzed, highly versatile, and high-yielding protocol for the synthesis of 2,4,5-triaryl-1H-imidazoles was developed through response surface methodology (RSM). The effects of different solvents, reaction paths, and phase-transfer catalysts (PTCs) in different concentrations were envisioned. Three independent variables (catalyst, catalyst loading, and solvent volume) identified by one-factor-at-a-time (OFAT) study were screened through full factorial design at two levels. The analysis of variance results suggested the significance of catalyst PEG400 and solvent glacial acetic acid at 5 h reaction. The optimum reaction conditions suggested by the RSM were the use of PEG400 (10.61 mol%) and glacial acetic acid (10.71 mL) for 5 h cycloocondensation. The experimental yield of 4,5-diphenyl-2-nitrophenyl-1H-imidazole (97%) was in agreement with predicted yield (97.5%).     

Solvent-free and catalyst-free method for the synthesis of 2,4,5-triarylimidazoles under microwave irradiation

A facile procedure for the synthesis of 2,4,5-triarylimidazoles is being reported starting from benzil, aromatic aldehyde and ammonium acetate. The reactions were carried out with catalyst-free, solvent-free and under microwave irradiation conditions in high yield (80–99%) with short time (3–5 min) and environmental benign, as well as convenient operation. The structures of the compounds have been confirmed on the basis of their IR, ¹H NMR, and/or ¹³C NMR, MS, and elemental analyzer.     

New environmentally-friendly solvent-free synthesis of imines using calcium oxide under microwave irradiation

Condensation of structurally diverse aldehydes including heterocyclic aldehydes, like furfural, with various amines in the presence of calcium oxide affording the corresponding imines in solvent-free conditions in good to excellent yields under microwave irradiation is described. A comparative study has been done under thermal conditions. The synergy between dry media and microwave irradiation in this reaction is evaluated by condensing less electrophilic aldehydes with poorly nucleophilic amines. The main advantages of this environmentally friendly protocol are the use of the non-toxic and inexpensive reagent calcium oxide and the considerable rate enhancement in comparison with a thermal reaction.     

Microwave-assisted synthesis of benzoxazinediones under solvent-free conditions

Benzoxazinediones exhibit potential as versatile synthons in the synthesis of wide variety of heterocyclic compounds with biological activity. In this work, an efficient and eco-friendly one-step synthesis of benzoxazine-2,4-diones from phthalic anhydrides derivatives and trimethylsilyl azide using the microwave technique was developed and compared with conventional heating. Microwave irradiation plays a critical role in driving the reaction and providing access to products and/or regioisomers not available from conventional heating. Thus, the regioselectivity of the reaction may be modulated by the irradiation time. Depending on the method employed the benzoxazinediones were isolated with yields in the range of 30–90%.     

Convenient,multicomponent, one-pot synthesis of highly substituted pyridines under solvent-free conditions

Highly substituted pyridine derivatives have been accessed through an efficient, one-pot, multicomponent reaction of aldehydes, malononitrile, and ammonium acetate in the presence of triethylamine as a catalyst under solvent-free conditions. This procedure affords the desired products in high purity and has advantages such as short reaction time, excellent yields, and simple workup procedure. This procedure affords the desired products in moderate to high yields and has such advantages as short reaction time and simple workup procedure.     

An efficient synthesis of 3-benzylquinazolin-4(1H)-one derivatives under catalyst-free and solvent-free conditions

Abstract

An efficient and convenient method for the preparation of 3-benzylquinazolin-4(1H)-one derivatives under solvent-free and catalyst-free conditions by the reaction of isatoic anhydride, benzylamine, and aromatic aldehydes was reported. In reported papers, ammonia water, ammonium salt, and aromatic amine were often used to synthesize quinazolin-4(1H)-one derivative, but benzylamine was seldom used in this synthesis. This article offers a green method for the synthesis of 3-benzylquinazolin-4(1H)-one derivative used benzylamine as starting material. This methodology has the advantages of short reaction time, mild reaction conditions, easy work-up, and environmental friendliness.     

Solvent-free synthesis of 4-aryl substituted 5-alkoxycarbonyl-6-methyl-3,4-dihydropyridones under microwave irradiation

4-Aryl substituted 5-alkoxycarbonyl-6-methyl-3,4-dihydropyridones have been prepared in one-pot condensation from Meldrum's acid, methyl acetoacetate and the appropriate benzaldehyde in the presence of ammonium acetate using microwave irradiation without solvent. This rapid method produced pure products in high yields (81-91%) due essentially to a specific non-thermal microwave effect (17-28%) by conventional heating under the same conditions.     

A novel one-pot synthesis of tetrasubstituted imidazoles under solvent-free conditions and microwave irradiation

The one-pot, three-component condensation of benzil, benzonitrile derivatives and primary amines on the surface of silica gel under solvent-free conditions and microwave irradiation provided tetrasubstituted imidazoles in high yields.