N-1,3,4- 口 恶 二唑基-N''-对溴苯氧乙酰基硫脲的合成及其抑菌活性

从对溴苯氧乙酸出发,先合成中间体酰基异硫氰酸酯,该中间体与2-氨基-5-芳基-1,3,4- 口 恶 二唑反应合成了10个新的苯氧乙酰基硫脲类化合物,其结构经元素分析、红外光谱、核磁共振氢谱和质谱确认。初步生物活性测试结果表明,在50 mg/L浓度下,所有目标化合物对水稻纹枯病菌Rhizatonia solani和黄瓜灰霉病菌Botrytis cinereapers的抑制率均达85％以上,部分化合物对黄瓜灰霉病菌的抑制率达100%。     

The effect of C-2-carboxyphenyl derivatives of certain heterocyclic compounds on root geotropism in cress seedlings

The effects on root geotropism of 2-carboxyphenyl derivatives of various five- and six-membered heterocyclic compounds have been assessed. In an assay involving cress seedlings, appropriately substituted derivatives of isoxazole, 1,3,4- and 1,2,4- oxadiazoles, 1,3,4-thiadiazole, 1,2,4-triazole, thiazoie, pyridine, pyrimidine and pyridazine were highly effective in eliminating the geotropic response.     

1,3,4(2H)‐Isoquinolinetriones: evaluation of amino‐substituted derivatives as redox mediator herbicides

Amino‐substituted derivatives of 2‐ethyl‐1,3,4(2H)‐isoquinolinetrione have been prepared with the aim of enhancing their hydrolytic stabilities relative to other isoquinolinetriones, and hence potentially improving their herbicidal effects. 5‐Amino‐2‐ethyl‐1,3,4(2H)‐isoquinolinetrione has been shown to be 12 and 8 times more stable towards hydrolysis than the isomeric 7‐ and 8‐amino derivatives, respectively, and 120 times more stable than 2‐ethyl‐1,3,4(2H)‐isoquinolinetrione itself. Pulse radiolysis studies have shown 5‐amino‐2‐ethyl‐1,3,4(2H)‐isoquinolinetrione to have free‐radical properties which could enhance the generation of superoxide radicals in plants. The compound is a potent stimulator of the light‐dependent consumption of oxygen at photosystem I in isolated chloroplasts and also shows high activity in isolated leaf discs. Evidence is presented which indicates that the rate of foliar uptake is a major factor affecting herbicidal activity for this compound. © 2000 Society of Chemical Industry     

N-(5-芳基-1,3,4-嗯二唑-2-基)-N''-α-萘乙酰基硫脲的合成及杀菌活性

从α-萘乙酸出发,合成酰基异硫氰酸酯,然后与2-氨基-5-芳基-1,3,4-嗯二唑反应合成了8个新的酰基硫脲类化合物 Ⅱa~Ⅱh 。所有化合物的结构均经元素分析、红外光谱、核磁共振氢谱和质谱确认。同时对6种病原菌进行了生物活性测试,结果发现,在50 mg/L下,所有目标化合物对黄瓜灰霉病菌Botrytis cinereapers的抑制效果较好,除 Ⅱa 外,其他化合物抑制率都达到80%以上。     

Synthesis and antifungal activity of 2‐azetidinonyl‐5‐(2‐benzoylphenoxy)methyl‐1,3,4‐oxadiazoles against seed‐borne pathogens of Eleusine coracana (L.) Gaertn

BACKGROUND: Finger millet is a major food crop as well as feed and fodder for livestock, especially in regions of southern India. A sturdy crop to fluctuating environmental conditions, it can be cultivated in all seasons of the year. Leaf, neck and finger blast caused by Pyricularia grisea Sacc. and Bipolaris setariae (Saw.) Shoem, as well as leaf spot disease, Bipolaris nodulosa (Berk & M.A.Curtis) Shoem, are major production constraints in southern India. Apart from environmental conditions, the use of harvested seeds by farmers is a major reason for disease prevalence. Benzophenone analogues have been investigated for controlling phytopathogenic fungi. In addition, the most important applications of azetidin‐2‐ones are as antibiotics. Based on this information, the present study was conducted to explore the antifungal activity of integrated 2‐azetidinonyl and 1,3,4‐oxadiazoles moieties into a benzophenone framework. RESULTS: A simple high‐yielding method for the integration of heterocyclic rings, namely 2‐azetidinonyl, at the benzophenone nucleus has been achieved, starting from substituted 2‐hydroxybenzophenones under mild conditions on a wet solid surface using microwave irradiation. In the present study, an array of newly synthesised compounds, 2‐azetidinonyl‐5‐(2‐benzoylphenoxy)methyl‐1,3,4‐oxadiazoles, were screened for their antifungal property against blast and leaf spot causing fungi associated with the seeds of finger millet, cv. Indof‐9. CONCLUSION: Two of the newly synthesised compounds showed promising effects in depleting the incidence of seed‐borne pathogenic fungi of finger millet. The suppression of Pyricularia grisea and Bipolaris setariae resulted in enhanced seed germination and seedling growth. Copyright © 2009 Society of Chemical Industry     

2-取代苯基-5-取代苯甲酰胺基-1,3,4-噻二唑的合成、抑菌活性及三维定量构效关系

以取代苯甲酸为起始原料，与氨基硫脲、三氯氧磷及取代苯甲酰氯进行缩合，制备了33个2-取代苯基-5-取代苯甲酰胺基-1,3,4-噻二唑 E ₁ ~E ₃₃ 。采用核磁共振氢谱 (1H NMR) 和高分辨质谱 (HRMS) 等对目标化合物的结构进行了确证及表征。采用菌丝生长速率法测定了目标化合物对根霉Rhizopus nigricans、青霉Penicillium glaucum、灰霉Botrytis cinerea、交链孢霉Alternaria brassicae和黑曲霉Aspergillus niger的体外抑菌活性。针对黑曲霉的抑制活性，分别利用CoMFA和CoMSIA对目标化合物进行了初步的三维定量构效关系 (3D-QSAR) 研究。结果表明，大部分化合物表现出良好的抑菌活性，在50 μg/mL下，化合物 E ₁ 、 E ₂ 和 E ₂₉ 对供试真菌的抑制率均达到80%以上，与对照药剂百菌清和多菌灵的抑菌效果相当。综合两种模型的结果，发现静电场的贡献值高于其他势场，且当苯环a的4位引入供电子基、苯环a的2位和6位以及苯环b上引入吸电子基时，有利于化合物抑菌活性的提高，可为进一步指导设计合成此类高活性化合物提供理论依据。     

2-杂环基-1,3,4-噁二嗪酮类化合物的合成及其除草活性

以取代杂环羧酸为起始原料,在1,3,4-噁二嗪-5-酮的2-位上分别引入呋喃环、吡啶环及氯代噻吩环,合成了31个未见报道的2-杂环基-1,3,4-噁二嗪酮化合物,其化学结构经核磁共振氢谱和元素分析确证。初步的生物活性测定结果表明,该类化合物具有良好的除草活性,如在质量浓度200 mg/L时,化合物 E14、E16、E20、E21 对马唐Digitaria sanguinalis的抑制率大于90%,化合物 E06、E07、E10、E14、E16、E20 对苋菜Ambrosia tricolor的抑制率也大于90%。     

A sensitive method for the determination of residues of N,N'-Bis(1,3,4-thiadiazol-2-yl)methanediamine in rice

A sensitive method for the isolation, clean-up and thin-layer chromatographic semi-quantitative determination of residues of N,N'-bis(1,3,4-thiadiazol-2-yl)methanediamine ( II ) in rice is reported. The residue from II in rice was found to be its degradation product 1,3,4-thiadiazol-2-ylamine ( I ). The mean recovery by this method was 85%, and the lowest limit of determination was 0.01 mg kg^?f. Using this proposed technique, the residues of I and II in various field-treated rice samples were studied.     

吡啶衍生物研究(V):2-[(2-氯吡啶)-4-基]-5-芳胺基-1,3,4-噻二唑的合成及杀菌活性

合成了一系列 2 - [(2 -氯吡啶 ) - 4 -基 ]- 5-芳胺基 - 1,3,4 -噻二唑类化合物 ,其结构经元素分析、1H NMR、和 13 C NMR确认。初步生物活性测定表明 ,合成化合物对某些真菌生长表现出较好的抑制活性 ,如 I- 0 2在 50 0 μMg· m L-1剂量下对水稻纹枯病菌生长的抑制率达87.5%。     

吡啶衍生物研究(IX):N-(1-甲氧羰基)乙基-N-[5-(2-氯吡啶-4-基)-1,3,4-噻二唑-2-基]酰胺的合成及除草活性

为了进一步研究前期发现的除草先导化合物2-仲丁氨基-5-(2-氯吡啶-4-基)-1，3，4-噻二唑(BCPT)的结构-活性关系并提高其除草活性，设计并合成了一系列N-(1-甲氧羰基)乙基-N-[5-(2-氯吡啶-4-基)-1，3，4-噻二唑-2-基]酰胺类化合物。其苗后除草活性测定结果表明，所有化合物的活性都远低于BCPT本身。说明BCPT可能具有与传统酰胺类除草剂不同的作用机制。     

1,3,4(2H)-isoquinolinetrione herbicides: Novel redox mediators of photosystem I

A series of 1,3,4(2H)-isoquinolinetriones have been found to be fast-acting post-emergence herbicides, producing symptoms of desiccation. These redox-active compounds are very potent stimulators of the light-dependent consumption of oxygen at photosystem I in isolated chloroplasts. Pulse radiolysis studies on 2-ethyl-1,3,4(2H)-isoquinolinetrione have shown it to have free-radical properties which could enhance the generation of superoxide radicals in plants. Electrochemical studies further support a redox mediator mode of action for the series. The compounds were found to be unstable towards hydrolysis, and this was considered to be a major factor limiting the overall herbicidal effects. Other parameters, related to uptake and/or translocation, which may limit the full expression of the herbicidal activity of certain compounds, are discussed.     

Studies on residues and the metabolic pathway of methidathion in tomato fruit

The residues and metabolism of methidathion [S-(2, 3-dihydro-5-methoxy-2-oxo-1, 3, 4-thiadiazol-3-ylmethyl) O, O-dimethyl phosphorodithioate] and its secondary metabolites: demethyl-methidathion [S-(2, 3-dihydro-5-methoxy-2-oxo-1, 3, 4-thiadiazol-3-ylmethyl) O-methyl O-hydrogen phosphorodithioate] ( IV ), the sulphide (2,3-dihydro-5-methoxy-3-methylthiomethyl-1,3,4-thiadiazol-2-one) ( I ), tsulphoxide(2,3-dihydro-5-methoxy-3- methylsulphinylmethyl-1,3,4-thiadiazol-2-one) ( II ) and the sulphone (2,3-dihydro-5-methoxy-3-methylsulphonylmethyl-1,3,4-thiadiazol-2-one ( III ) were studied in laboratory-treated tomato fruit. The metabolites and residues of methidathion were determined for the applied doses of 1, 7 and 14 mg of methidathion kg^?1 of fruit. Methidathion was metabolised extensively over a 14-day period. The amount of metabolites formed was a function of both the applied dose as well as the time after application. Major water-soluble metabolites were found to be IV and the cysteine conjugate S-(2,3-dihydro-5-methoxy-2-oxo-1,3,4-thiadiazol-3-ylmethyl)-L-cysteine ( VI ). The chloroform-soluble metabolites were identified as the oxygen analogue of methidathion [S-(2,3-dihydro-5-methoxy-2-oxo-1,3,4-thiadiazol-3-ylmethyl) O, O-dimethyl phosphorothioate] ( V ), the sulphoxide II , and the hydroxy compound 2,3-dihydro-3-hydroxymethyl-5-methoxy-1,3,4-thiadiazol-2-one. The oxygen analogue of methidathion ( V ) was found in small amounts, corresponding to <5% of the added methidathion. Demethyl-methidathion ( IV ) appeared to be a precursor in the formation of the cysteine conjugate VI . The sulphide I seemed to be more reactive in forming the cysteine conjugate than the sulphoxide II or the sulphone III .     

Synthesis and insecticidal activity of novel 1,3,4-oxadiazolin-5-one and pyrazolin-5-one derivatives

A series of novel 2-(2,4,6-trisubstituted phenyl)-1,3,4-oxadiazolin-5-one derivatives and 3-(2,4,6-trichlorophenyl)pyrazolin-5-one derivatives were synthesized and evaluated for insecticidal activity. It was found that a moderately bulky alkyl group, such as a tert-butyl group, on the heterocyclic ring, and a trifluoromethyl group on the benzene ring were optimal substituents on the molecule. The oxygen atom in the oxadiazoline ring was essential for insecticidal activity. Of the compounds assayed, 4-tert-butyl-2-(2,6-dichloro-4-trifluoromethylphenyl)-1,3,4-oxadiazolin-5-one gave the highest activity against Nephtotettix cincticeps, with an LC₅₀ value of 0.51 mg litre⁻¹. © 1999 Society of Chemical Industry     

苯甲酰脲类化合物的合成及杀虫活性

对2-氨基-5-芳基-1,3,4- 口 恶 二唑的合成进行了深入研究,找到了一种基于HBr-H2O2 体系的绿色合成新方法,并以此为中间体,合成了18个未见报道的苯甲酰脲类目标化合物,所有化合物均通过核磁共振、高分辨质谱、红外光谱的分析鉴定。生物活性测试结果表明,在500 mg/L浓度下该系列目标化合物均未表现出显著的杀虫活性。     

含硝基亚氨基咪唑烷脲类化合物的合成及生物活性

为了寻找新的高效烟碱类杀虫剂,用异氰酸酯与2-硝基亚氨基咪唑烷反应,得到10个含硝基亚氨基咪唑烷脲类新化合物,其结构均通过IR、1H NMR和元素分析确认。初步的生物活性试验结果表明, 3 号化合物在0.1 kg/hm2 时对马唐Digitaria sanguinalis的抑制率为64.5%, 6 号化合物在0.2 mg/L时对豆蚜Aphis craccivora Koch的致死率为67％。     

2-甲硫基-1-苯基乙酮苯甲酰腙类化合物的合成和生物活性

为寻找新型结构的农药先导化合物,采用2-甲硫基-1-取代苯基乙酮与取代苯甲酰肼反应合成了11个2-甲硫基-1-苯基乙酮苯甲酰腙类化合物,其化学结构经质谱、1H核磁共振与元素分析确证。生物活性试验结果表明,部分化合物具有杀菌或杀虫活性,如2-甲硫基-1-(4-甲基苯基)乙酮-4-氯苯甲酰腙( Ⅲj )在500 mg/L时对黄瓜灰霉病菌B.cinerea、小麦赤霉病菌G.zeae具有良好的杀菌活性,其抑制率达到95%以上。     

吡啶衍生物研究(X):2-仲丁氨基-5-(2-芳氧吡啶 -4-基)-1,3,4-噻二唑的合成及除草活性

为了研究2-仲丁氨基-5-(2-氯吡啶-4-基)-1,3,4-噻二唑(BCPT)的结构-活性关系和开发活性更高的新型除草剂,以BCPT为先导化合物,依据活性亚结构连接法,在吡啶环2-位上引入二芳醚类除草剂的典型结构单元——芳醚,设计并合成了一系列新的芳氧吡啶噻二唑类化合物,其结构经元素分析和1H NMR确证。初步除草活性测定结果表明,在500 mg/L剂量下,所有化合物的除草活性(抑制率0~45%)远低于先导化合物(抑制率72％~87%),说明吡啶环2-位上的氯原子可能对维持该类化合物的除草活性是必需的。     

Synthesis and screening of a new group of fungicides: 1-(2-phenyl-1,3-dioxolan-2-ylmethyl)-1,2,4-triazoles

A series of substituted 1-(2-phenyl-1,3-dioxolan-2-ylmethyl)-1,2,4-triazoles has been prepared and evaluated in the glasshouse for fungicidal activity. Compounds with 2,4-dichloro substitution on the phenyl ring and with a lower alkyl side chain on dioxolane ring were found most promising for the control of powdery mildew gherkins and barley and for the control of bean rust. These compounds were systemically active and some are being developed commercially for various applications.     

吡啶衍生物研究(Ⅺ):2-仲丁胺基-5-(2-氯吡啶-4-基)-1,3,4-噻二唑对映异构体的合成及除草活性

2-仲丁胺基-5-(2-氯吡啶-4-基)-1,3,4-噻二唑(BCPT)是早期发现的一个具有良好除草活性的外消旋先导化合物,报道了使用R/S-仲丁胺为原料分别合成BCPT的两个对映异构体的方法。初步生测结果显示,3种噻二唑化合物(外消旋体和两个对映异构体)对稗草的根和茎均表现出较强的抑制作用,其中S-(+)对映异构体对茎的抑制作用强于R-(-)对映异构体和外消旋体,但对根的生长抑制作用三者间没有显著差异。     

New 2-phenyl-4,5,6,7-tetrahydro-2H-indazole derivatives as paddy field herbicides

A series of 3-chloro-2-(4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-2H-indazole derivatives containing various substituted isoxazolinylmethoxy groups at the 5-position of the benzene ring were synthesized and their herbicidal activities assessed under greenhouse and flooded paddy conditions. Among them, compounds having a phenyl or cyano substituent at the 3-position of the 5-methyl-isoxazolin-5-yl structure demonstrated good rice selectivity and potent herbicidal activity against annual weeds at 16-63 g AI ha(-1) under greenhouse conditions. Field trials indicated that these two compounds controlled a wide range of annual weeds rapidly with a good tolerance on transplanted rice seedlings by pre-emergence application. They showed a low mammalian and environmental toxicity in various toxicological tests.