含酰基吡唑啉酮和咔唑光功能基元的新型席夫碱的合成

以苯肼、乙酰乙酸乙酯和咔唑为原料,合成了一种含酰基吡唑啉酮和咔唑双光功能基元的新型席夫碱———1-苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5缩N-对氨基苄基咔唑(6),其结构经1H NMR和IR确证;采用UV-vis对其电子结构进行了初步研究,与酰基吡唑啉酮或咔唑功能基元相比,6表现出特殊的电子结构。     

1-芳基-4-吡唑-5-酰基氨基脲类化合物的合成及杀菌活性

为了寻求新的吡唑先导化合物, 用4-氯-1-甲基-3-乙基-5-吡唑甲酰肼与取代苯基异氰酸酯反应得到了14个新的1-吡唑酰基-4-芳基氨基脲类化合物. 经IR, 1H NMR, MS和元素分析对化合物的结构进行了表征. 初步生物活性实验结果表明, 在500 mg/mL浓度下, 化合物1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-(2-甲基苯基)氨基脲(4g), 1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-(2,4-二甲基苯基)氨基脲(4k)对小麦白粉病菌(Blumeria graminis)的抑制率分别达到90%和80%; 在25 mg/mL浓度下, 化合物1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-苯基氨基脲(4c)对黄瓜灰霉病菌(Botrytis cinerea)的抑制率达到70.1%; 化合物1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-苯基氨基脲(4c)和1-(4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基)-4-(2-硝基苯基)氨基脲(4d)对稻瘟病菌(Pyricularia oryzae)的抑制率均达到51.3%.     

1-对硝基苯基-3-甲基-4-(α-噻吩甲酰基)-5-吡唑啉酮的合成

对硝基苯肼与乙酰乙酸乙酯经亲核闭环制得1-对硝基苯基-3-甲基-5-吡唑啉酮(1);1与α-噻吩甲酰氯进行克莱森缩合合成了新化合物——1-对硝基苯基-3-甲基-4-(α-噻吩甲酰基)-5-吡唑啉酮,其结构经1H NMR,13C NMR,IR,MS和元素分析表征。     

新型吡唑啉酮衍生物的制备

以氢氧化钾为催化剂,1-苯基-3-甲基-吡唑啉-5-酮与取代苯甲醛亚胺反应合成了新型1-苯基-3-甲基-吡唑啉-5-酮衍生物——1-苯基-3-甲基-4-(1-N-氯乙胺基-1-取代苯基)甲基-吡唑啉-5-酮,其结构经1H NMR,IR,MS和元素分析表征。     

新型吡唑啉酮衍生物的固相合成

以2-苯基-1,2,3-三唑-4-甲醛和3-甲基-1-苯基-5-吡唑啉酮为原料,采用微波辐射固相合成法,经Knoeve-nagel缩合反应制得3-甲基-1-苯基4-(2-苯基-1,2,3-三唑4-亚甲基)-5-吡唑啉酮(2);2与吲哚发生Michael加成反应合成了吡唑啉酮衍生物,其结构经1H NMR和IR确证.     

一种新的双吡唑啉酮化合物的合成及晶体结构

4-酰基吡唑啉酮是一类含有氮杂环的β-二酮型螯合剂,近几十年来,国内外对该类化合物及其衍生物进行了广泛的研究[1-3].本室验室曾合成了一系列4-苯甲酰基吡唑啉酮缩氨基硫脲及其衍生物,发现这类含硫席夫碱具有光致变色性,并对其变色机理和反应动力学进行了详细研究[4,5].作为工作的继续,我们又合成了1-苯基-3-甲基-4-乙酰基-5-吡唑啉酮缩硫甲基氨基硫脲(PMEP-MTTSC),虽然此化合物不具有光致变色性,但在培养其单晶的过程中,却意外地得到了一种双吡唑啉酮化合物.当用不同的溶剂来培养其单晶时,又得到了这种双吡唑啉酮的一对互变色异构体.反应过程如下:     

无溶剂无催化剂微波促进下 1-苯基-3-甲基-5-吡唑啉酮与芳醛的反应研究

无溶剂无催化剂条件下,微波促进1-苯基-3-甲基-5-吡唑啉酮与芳醛的缩合反应选择不同辐射功率将分别得到4-芳亚甲基-3-甲基-1-苯基-5-吡唑啉酮和4,4′-芳亚甲基-双(1-苯基-3-甲基-5-吡唑啉酮),产率良好.产物结构经1H NMR,13CNMR和IR进行了表征.     

1-苯基-3-苯基-4-对氟苯亚甲基-5-吡唑啉酮缩4-苯基氨基脲光致变色化合物的合成及其光谱研究

有机光致变色化合物如螺吡喃、螺噁嗪、俘精酸酐等,由于它们在信息记录、信息处理、各种发射材料和分子开关等领域有广阔的应用前景,因而引起了人们的广泛关注[1,2],但对含吡唑啉酮缩氨基脲类光致变色化合物的研究还鲜有报道[3,4].本文按1:1摩尔比称取1-苯基-3-苯基-4-对氟苯甲酰基-5-吡唑啉酮和4-苯基-氨基脲置于圆底烧瓶中,加入适量乙醇,于80℃下搅拌回流8 h,析出沉淀.洗涤、干燥得1-苯基-3-苯基-4-对氟苯亚甲基-5-吡唑啉酮缩4-苯基-氨基脲光致变色化合物.用紫外漫反射光谱研究了其在固态时的光致变色行为及其动力学反应.实验表明该化合物在固态具有明显的光致变色性质,经365 nm紫外光照射一段时间后,在355～455 nm之间出现了一新峰,且该峰的强度随光照时间的延长而增加,同时伴随着颜色发生改变,即由白色逐渐变为黄色.而且还发现该化合物的光致变色过程遵循的是一级动力学反应,其速率常数k=3.857×10-4s-1.     

新型含吡唑基1,2,4-三唑衍生物的合成

以1-苯基-3-甲基-5-吡唑啉酮为起始原料,经氯甲酰化、氧化、酯化、肼解、成盐及闭环反应制得4-氨基-5-(1-苯基-3-甲基-5-氯吡唑)-1,2,4-三唑-3-硫酮(6);6与苯甲醛经缩合反应制得4-苯甲亚胺基-5-(5-氯-3-甲基-1-苯基)吡唑-4H-1,2,4-三唑-3-硫酮(7);7与对硝基苄氯反应合成了2个新型含吡唑基1,2,4-三唑化合物,其结构经1H NMR,IR和元素分析表征。     

酰基吡唑啉酮化合物的计算、合成和抑菌活性

利用Sybyl 6.3软件包中的分子力学程序对2个4-酰基-2-吡唑啉-5-酮类化合物分子进行了系统研究,得到了它们的最低能量构象,发现它们具有适宜的配位环境,可能是一类新型的三齿配体。 合成和表征了1-苯基-3-甲基-4-(邻-甲酰基苯甲酸)-2-吡唑啉-5-酮 和1-苯基-3-甲基-4-(顺-乙酰基丁烯酸)-2-吡唑啉-5-酮化合物。 抑菌活性测定结果表明它们对革兰氏阳性和阴性菌均有较好的抑制作用,为进一步研究其配合物的生理活性提供了参考依据。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.