N-(取代嘧啶-2'-基)-2-三氟乙酰氨基苯磺酰脲的合成及除草活性

磺酰脲类除草剂是近 2 0年来开发出的超高效、广谱、低毒和高选择性除草剂 .在已研究的磺酰脲分子中 ,芳环的邻位取代基多为酯基、卤素、取代烷氧基、三氟甲基等 [1,2 ] ,而邻位取代基为酰胺基的甚少 .为寻找高活性的磺酰脲化合物 ,本文将活性基团三氟乙酰氨基引入磺酰脲分子中 ,合成了 1 0种 N - (取代嘧啶 - 2 -基 ) - 2 -三氟乙酰氨基苯磺酰脲 (其中 9种为新化合物 ,4b～ 4j) ,并改进了实验方法 ,使产率明显提高 .同时还测定了它们的除草活性 ,其中一些化合物具有良好的活性 .合成路线如下 :　　 X- 4数字显示显微熔点仪 ,温度计未校正…     

苯环2-位不同酯基取代的磺酰脲类化合物的合成及其除草活性

以正在开发的磺酰脲类超高效除草剂NK94827[N'-(4'-甲基嘧啶-2'-基)-2-甲氧羰基苯磺酰脲]的基本结构为基础,设计合成了18个苯环2位不同酯基取代的的新型磺酰脲类化合物,产物结构均经¹HNMR及元素分析确证.经油菜平皿法和盆栽试验测试除草活性,所合成的部分磺酰脲化合物的除草活性高.     

N-(4-取代嘧啶-2-基)苄基磺酰脲和苯氧基磺酰脲的3D-QSAR研究

采用比较分子力场分析(CoMFA)方法,对两类单取代嘧啶类似物、6个N-(4-取代嘧啶-2-基)-2-甲氧羰基苄基磺酰脲(1a～1f)和14个N-(4-取代嘧啶-2-基)-2-取代苯氧基磺酰脲(2a～2n)进行三维定量构效关系(3D-QSAR)研究.建立了一个较为可靠的预测模型.结果表明,分子中苯环邻位、嘧啶环形成氢键的N原子处以及嘧啶环4位和6位附近负电荷增加;苯环邻位乙氧基的CH₂CH₃附近选择带正电的原子;苯环邻位乙氧基附近空间体积增加,而嘧啶环4位甲氧基稍远处取代基的立体位阻不超过此位置,将有利于提高活性.最后解释了修饰磺酰脲的除草剂仍具有较高活性的原因.     

嘧啶的研究:氯和硫醇嘧啶类的作用:4-甲基-5-正丙基-6-氨基-2-氧嘧啶的合成

1. 2-乙硫基-4-甲基-5-正丙基-6-氯代嘧啶在甲醇溶液与甲醇钠相互作用,和在乙醇溶液与乙醇钠互相作用,分别得到相应的嘧啶-甲醚及嘧啶-乙醚。2. 氯对2-乙硫基-4-甲基-5-正丙基-6-氯代嘧啶,2-乙硫基-4-甲基-5-正丙基-6-甲氧基嘧啶及2-乙硫基-4-甲基-5-正丙基-6-乙氧基嘧啶起作用,得到相应的嘧啶砜,用氯在水溶液中氧化硫醇嘧啶化合物(Ⅰ),此反应是特殊的,对嘧啶环中的双键没有影响,祇有硫醇基团氧化而得到相应的稳定的嘧啶砜(Ⅱ)。3. 将醇氨与2-乙磺醯基-4-甲基-5-正丙基-6-氯代嘧啶作用时,对于2-位上的磺醯基不起反应,取代于6-位的氯被置换为氨基而得到2-乙磺醯基-4-甲基-5-正丙基-6-氨基嘧啶。4. 硷对2-乙磺醯基-4-甲基-5-正丙基-6-乙氧基嘧啶及2-乙磺醯基-4-甲基-5-正丙基-6-甲氧基嘧啶作用,分别得到2-氧代-4-甲基-5-正丙基-6-乙氧基嘧啶及2-氧代-4-甲基-5一正丙基-6-甲氧基嘧啶,因此,嘧啶砜中在2-位的磺醯基与硷反应时被置换为羟基,而取代于6-位的乙氧基和甲氧基则不起反应。5. 叙述了一种合成2-氧代-4-甲基-5-正丙基-6-氨基嘧啶(或1,2-二氢化-2-酮-4-氨基-5-正丙基-6-甲基嘧啶)的新方法。     

嘧啶的研究:氯对硫醇嘧啶的作用2-酮-4-氨基-5,6-二甲基-1,2-二氢-嘧啶的合成

1.甲醇鈉對於2-乙硫醇基-4,5-二甲基-6-氯代嘧啶在甲醇溶液中生成相應的乙硫醇基嘧啶甲醚。 2.氯對於2-乙硫醇基-4,5-二甲基嘧啶衍生物(I),在水溶液中的作用是特殊的,嘧啶中的不飽和現象不被氯化反應改變而硫醇基團被氧化,形成穩定相應嘧啶碸的衍生物(II),因此製備了2-乙磺醯基-4,5-二甲基-6-甲氧基嘧啶和2-乙磺醯基-4,5-二甲基-6-氯代嘧啶. 3.2-乙硫醇-4,5-二甲基-6-甲氧基嘧啶在甲醇中進行氯化反應,現象甚複雜,並且嘧啶碸的產量很低,2-乙硫醇-4,5-二甲基-6-甲氧基嘧啶在甲醇中被氯氧化,首先形成嘧啶碸,後者並不穩定,再與氯作用形成乙磺醯氯和2-氯代-4,5-二甲基-6-甲氧基嘧啶。 4.嘧啶碸與鹼作用,乙磺醯基被羥基取代,同時在嘧啶環6位上的乙氧基保留,因此2-乙磺醯基-6-甲氧基-4,5-二甲基嘧啶與鹼作用,形成2-酮-5,6-二甲基-4-甲氧基-1,2-二氫嘧啶。 5.酒精-氨的溶液作用在氯代乙磺醯基嘧啶得到氨基-乙磺醯基嘧啶,在氯代乙磺醯基嘧啶中,嘧啶環上2位的乙磺醯基仍保留,而6位土的氯被氨基取代。 6.本文敘述了合成4,5-二甲基-2-氧代-6-氨基嘧啶(或2-酮-4-氨基-5,6-二甲基-1,2-二氫化嘧啶)的新方法。     

新型苯并咪唑衍生物的合成及其抗凝血活性

以3-［(3-氨基-4-甲基氨基苯甲酰)吡啶-2-基氨基］丙酸乙酯为原料,与4-氰基-3-氟苯取代基乙酸经环化反应制得3-【【2-｛［(4-氰基-3-氟苯取代基）甲基］-1-甲基-1-H-苯并咪唑-5-基｝羰基】吡啶-2-基】氨基丙酸乙酯（3a, 3e）; 3经水解和酰胺化反应制得3-【【【2-｛［(4-氰基-3-氟苯基)取代基］甲基｝-1-甲基-1H-苯并咪唑-5-基】羰基】吡啶-2-基氨基】丙酰取代胺基（6a~6h）;6与乙酰氧肟酸经环合反应合成了8个新型的苯并咪唑衍生物（7a~7h）,其结构经1H NMR和HR-ESI-MS表征。抗凝血活性结果表明： 7a和7c的抗凝血活性最好,其aPTT值分别为(83.1±4.2) s和(80.7±2.9) s,优于阳性对照药达比加群酯(75.3±2.1)s。     

新(4′-三氟甲基嘧啶基)-2-苯磺酰脲衍生物的合成及生物活性

以单取代苯磺酰脲除草剂NK92825和NK94827为基础,将三氟甲基引入嘧啶环中,设计合成了17个新的4′-三氟甲基嘧啶苯磺酰脲化合物,产物结构均经1H NMR及元素分析确证.目标化合物经盆栽试验,结果表明,部分化合物有较好的除草活性.     

三嗪基苯硫甲基磺酰脲的合成

苯硫甲基磺酰胺(1)与4,6-二氯-2-三嗪异氰酸酯以碳酸钾为触媒在甲苯中加热回流制得N-4,6-二氯-2-三嗪基苯硫甲基磺酰脲(2),后者进一步与甲醇钠作用得N-4,6-二甲氧基-2-三嗪基苯硫甲基磺酰脲(3)。化合物3d经测试,具有一定的除草活性。     

高效低毒除草剂氟嘧磺隆的合成

以硫脲和丙二酸二乙酯为起始原料,通过环化、甲基化、双氟甲氧基化、氧化、氨解、缩合6步单元反应,合成氟嘧磺隆(primisulfuron,Ⅵ)及中间体Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ,反应总收率达30%. 在甲醇钠作用下,硫脲和丙二酸二乙酯环化得到中间体Ⅰ,再经巯基与硫酸二甲酯反应得到中间体Ⅱ,再经羟基与二氟一氯甲烷反应得到中间体Ⅲ,再经S原子被H2O2氧化得中间体Ⅳ,其甲基砜基团被氨基取代得中间体Ⅴ,目标产物Ⅳ由中间体Ⅴ与邻甲氧羰基苯磺酰异氰酸酯反应得到. 化合物Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ的结构通过1H NMR、MS进行确证,其纯度通过HPLC进行检测.     

新型含氟酰胺化羟甲香豆素衍生物的合成及生物活性

以羟甲香豆素为先导,利用活性亚结构拼接原理,通过引入三氟甲基及酰胺基,设计、合成了系列新型含氟酰胺化羟甲香豆素衍生物,其结构用~1H NMR、~(13)C NMR、HRMS表征,N-正丁酰基-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆素(f1)及N-对甲苯甲酰基-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆素(f9)的结构经X射线单晶衍射进一步确证.除草活性初筛表明,化合物f1、N-苯乙酰基-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆素(f13)、N-甲基丙烯酰基-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆素(f5)、N-环丙甲酰基-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆素(f7)及N-(6-氯烟酰基)-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆素(f20)对马唐幼茎的生长具有强烈抑制作用,f9、f7及N-(萘-2-甲酰基)-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆素(f17)对灰藜幼茎生长具有良好抑制作用,其抑制率高于对照药剂乙草胺.作物安全评价结果表明,化合物f1、f9及f13对双子叶作物白菜及油菜比较安全,对单子叶作物小麦及高粱比较敏感.抑菌活性评价表明,N-间溴苯甲酰基-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆(f12)、f7及f9对番茄灰霉病菌具有较好抑制作用,N-氢化肉桂酰基-N-间氟苄基-6-氨基-7-甲氧基-4-三氟甲基香豆素(f14)对苹果腐烂病菌具有较好抑制作用.     

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%.     

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.     

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.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

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.