磺酰脲类除草剂残留检测技术及其研究进展

磺酰脲类除草剂具有高效、低毒、低残留等特点,已经成为当前使用量最大的一类除草剂.随着该类除草剂在农业生产中的广泛使用,其残留问题以及对后茬作物产生的危害已经引起关注.由于磺酰脲类除草剂在环境和生物样品中痕量存在,且其化学和热不稳定,酸性条件下易水解,以及最大残留限量值日益严格,使其残留分析成为一项极具挑战性的工作.该文综述了近年来磺酰脲类除草剂残留分析的前处理方法和检测技术的研究进展,并详细介绍了分子印迹技术、在线联用技术和液相色谱-串联质谱技术在该类除草剂检测中的应用及其前景,为今后分析检测各类样品基质中磺酰脲类除草剂的残留提供参考和依据.     

磺酰脲类除草剂的合成及其除草活性

磺酰脲类除草剂具有用量低,活性高、选择性好、毒性小的优点。为开发和应用此类除草剂,我们合成了在氮原子上连正丁基的8个新的衍生物,并进行了室内药效测定。     

磺酰脲除草剂分子与受体作用的初级模型

磺酰脲除草剂分子与受体作用的初级模型赖城明，袁满雪，李正名，贾国锋，王玲秀（南开大学元素有机化学国家重点实验室化学系，天津，３０００７１）（南开大学元素有机化学研究所）关键词磺酰脲分子，受体作用模型，构效关系磺酰脲类具有超高效除草性能。Ｓｃｈｌｏｓｓ...     

磺酰脲类除草剂分子印迹聚合物制备及应用研究进展

磺酰脲类除草剂本身易降解,在环境和生物样品中痕量存在,其残留分析工作颇具挑战。分子印迹聚合物因其良好的选择性和稳定性已被广泛应用于农药残留分析的分离与富集前处理过程,提高了检测的准确度和精密度。本文从单体、溶剂与致孔剂、聚合方法三个方面概述了近15年来磺酰脲类分子印迹聚合物的制备,并对其在残留检测中的应用方式进行了综述,为磺酰脲类除草剂残留检测技术的进一步开发提供了参考。     

单嘧磺隆原药组成的定性和定量分析

磺酰脲类除草剂作用于乙酰乳酸合成酶(ALS),对温血动物几乎无毒,磺酰脲活性分子必须含有胍桥,在胍桥间位须为双取代,而对位不能有任何取代基,分子中还须有一个杂环系统,前文从室内筛选出发,发现部分单一取代杂环的磺酰脲化合物也具有足够的除草活性,     

新磺酰脲类化合物的合成及除草活性

新磺酰脲类化合物的合成及除草活性;嘧啶;合成;除草剂     

1,2,4-三唑并［1,5-a］嘧啶-2-磺酰胺类除草剂的CoMFA研究

１,２,４－三唑并「１,５－ａ」嘧啶－２－磺酰胺类除草剂是继磺酰脲之后所开发出的又一类以ＡＬＳ为作用靶标的超高效除草剂,本文采用比较分子力场分析方法对该类除草剂进行了三维定量构效关系研究,,结果发现立体场和静电场对该类化合物的除草活性均有重要影响,其中以立体场搂主,根据我们所得的ＱＳＡＲ模型,可以对该类化合物的结构与活性关系进行很好的解释。     

邻烷氧基羰基苯磺酰胺衍生物的合成、表征及生物活性

磺酰胺类化合物是继磺酰脲与咪唑啉酮除草剂之后开发的乙酰乳酸合成酶 (ＡＬＳ)抑制剂的另一重要领域 ,已筛选出一些高活性的新品种[1～ 3] 。为寻找新的性能优良的活性物质 ,进一步研究活性与结构的关系 ,本文设计将磺酰胺类和酰胺类除草剂的基本骨架用一个亚甲基 ＣＨ2 连结起来 ,相当于在磺酰脲桥链中间插入了一个亚甲基 ,共合成了 1 6个新的邻烷氧基羰基苯磺酰胺衍生物( 2ａ～ 2ｐ) ,并初步测试了它们的生物活性。1　实验部分1 1　仪器和试剂ＪＥＯＬＦＸ 90Ｑ型、ＢＲＵＫＥＲＡＣ Ｐ2 0 0型核磁共振仪 ,ＴＭＳ为内标 ;Ｓｈｉｍａｄ…     

高效液相色谱法同时测定大豆中10种磺酰脲类除草剂的残留量

首次建立了同时检测大豆中10种磺酰脲类除草剂(环氧嘧磺隆、噻吩磺隆、甲磺隆、醚苯磺隆、氯磺隆、苄嘧磺隆、氟磺隆、吡嘧磺隆、氯嘧磺隆和氟嘧磺隆)多残留量的反相高效液相色谱(RP-HPLC)方法。样品经乙腈提取、正己烷液-液分配、Florisil填充柱净化后,采用RP-HPLC-二极管阵列检测器检测(DAD)法测定,外标法定量。对样品前处理和色谱分离条件进行了详细的研究和优化。10种磺酰脲类除草剂的质量浓度在0.1~10.0 mg/L范围内其浓度与峰面积的线性关系良好,相关系数为0.9996~0.9997;在     

含磺酰胺的苯氧乙(丙)酸酯的合成与除草活性

磺酰脲(胺)作为一类抑制乙酰乳酸合成酶(ALS)活性的除草剂,具有剂量小,选择性强,杀草谱广,对哺乳动物毒性低,在环境中不易积聚等特点,成为除草剂研究的热点[1-4].本文采用"亚结构连接法",将含饱和杂环(芳环)磺酰胺引入到芳氧羧酸中,试图降低药物对作物产生的毒副作用与抗药性,同时提高其除草活性.8个目标化合物的合成路线如下:     

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.     

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.     

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.     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.