2,4-二氯-5-异丙氧基苯胺的合成

1 前言 2,4-二氯-5-异丙氧基苯胺是重要的染料、医药和农药中间体,特别是合成1,2,4,5- 四取代苯类含氮杂环除草剂如口恶草酮、2-[2,4-二氯-5 -(1-甲基乙氧基)苯基]-4-(2-氟乙基)-1,2,4-三嗪-3,5(2H,4H)-二酮等.该中间体合成未见国内文献报道.专利WO 8600072中报道路线是采用间氨基苯酚经酰化、氯化、水解、醚化制得产品(见方程1).     

2-取代-4(5)-烷氧基咪唑的合成

我们曾报道了N-氰甲基苯甲亚氨酸乙酯(1a)的烷基化反应、Micheal加成和与芳醛的缩合反应。本文报道碱催化下N-氰甲基亚氨酸乙酯在醇中的成环反应结果。在固-液相转移催化条件下,N-氰甲基苯甲亚氨酸乙酯(1 a)与丙烯酸甲酯反应,生成Micheal加成产物。当用乙醇钠作碱、乙醇作溶剂时,1a与丙烯酸甲酯反应没有生成Micheal     

7-十二烯基-8-羟基喹啉的合成

7-十二烯基-8-羟基喹啉是一种新型螯合型萃取剂(Kelex 100的主要成份)。它是(1a)和(1b)异构体的混合物。本文报道了利用1-氯-1,1,3,3-四甲基丁烷与过量丁二烯-[1,3]的1,4加成反应合成重要中间体1-氯-5,5,7,7-四甲基辛烯-[2](3)的方法,此法具有室温、常压、产率高、设备简单、操作方便等优点。     

1-磷酰肼基-2-(1H-1,2,4-三唑-1-基)-4,4-二甲基-3-戊酮的合成及生物活性

由 2 -( 1H -1 ,2 ,4 -三唑-1 -基 ) -4 ,4 -二甲基-1 -戊烯 -3 -酮和 (硫代 )磷 (膦 )酰肼的亲核加成反应合成了六个未见文献报道的目标化合物 ,其化学结构经IR、1HNMR、MS和元素分析确证。目标化合物的生物活性数据表明 ,该类化合物对小麦锈病有较好的防治效果。     

1H-吡唑-4-甲酸的合成改进

以氰乙酸乙酯和原甲酸三乙酯为原料,通过Claisen酯缩合、合环、脱氨和水解得到1H-吡唑-4-甲酸.用质谱(MS)、核磁共振氢谱(1HNMR)和核磁共振碳谱(13C NMR)表征了化合物的结构.实验结果表明,1H-吡唑-4-甲酸的收率由文献报道的70%提高到了97.1%.     

(S)-(+)-6,7-丙酮缩二醇-3-酮-庚酸乙酯的合成研究

首次报道利用丙二酸亚异丙酯钠盐与γ-丁内酯类化合物反应,制备β-酮酯类衍生物。以(S)-(+)-谷氨酸为起始物经重氮化、环合,加成开环及酯化等反应,成功地合成了(S)-(+)-6,7-丙酮缩二醇-3-酮-庚酸乙酯。化合物(1)、(5)、(6)未见文献报道。     

2-氨基取代噻唑基膦酸酯的合成

许多噻唑类化合物具有生物活性,有些已作为杀菌剂、除草剂在农业上得到应用。近年来还进行了α-氨基酸的类似物α-氨基膦酸的合成及其生物活性的研究。迄今为止,还未见有4-噻唑基膦酸酯类化合物的合成和生物活性方面的文献报道。本文报道一系列2-氨基-5-取代-4-噻唑基膦酸酯(1)和2-氨基-4-取代-5-噻唑基膦酸酯(2)的合成。这类化合物显示了一定的杀菌活性。 1由取代乙酰氯与亚磷酸三酯经Arbuzov反应得到的取代乙酰基膦酸三酯(3)与缩二硫脲的溴氢酸盐(4)、一定量的弱碱(如硫脲、乙酸钾)在乙醇中反应制得。溶剂和碱的强弱     

4-烷氧基苯甲醛-4-氨基安替比林希夫碱的合成及抑菌活性

报道了4-氨基安替比林与4-烷氧基苯甲醛缩合反应生成希夫碱的合成和抑菌活性,分子结构由1HNMR、IR和元素分析表征;抑菌活性测定结果表明,化合物(5a,5d,5e,5f,5g)对金黄色葡萄球菌、大肠杆菌、枯草杆菌、黑霉菌、青霉菌(抑菌环直径15.3 ～ 21.70 mm)均有较好的抑菌活性,其中化合物(5f)对黑霉菌(抑菌环直径26.20 mm)有优良的抑菌活性.     

24-亚甲基胆甾-5-烯-3β,19-二醇的合成

从豆甾醇出发,通过10步反应,合成得到具有显著细胞毒活性的24-亚甲基胆甾-5-烯-3β,19-二醇(1),总产率为16%.目标产物1的熔点、[α]值和波谱数据与天然产物一致.化合物1的合成是首次报道,它对人体鼻咽癌(CN2)和胃癌(Mgc803)细胞有显著抑制活性.     

前列腺素中间体2-(6′-甲氧羰己基)环戊-2-烯-1-酮的合成

标题化合物(1)是合成11-去羟前列腺素E_1(PGE_1)及其衍生物的重要中间体。在引入羟基后所得化合物2是用1,4-加成法合成PGE_1及其衍生物的关键中间体。因此最近几年文献中对合成1的研究仍有不少报道。我们曾从环戊酮合成1。现在本文报道另一种合成1的方法。一般应用Grignard试剂与酰氯反应制备酮时,由于会进一步生成叔醇而使实际应用受到限制。Stowell发现2-(2′-溴乙基)1,3-二氧六环(3)的Grignard试剂与酰氯的反应可以完全控制在形成酮的阶段,因此我们使用3的Grignard试剂与壬二酸单乙酯的酰     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.