Antimicrobial activity of some N-(arylalkyl)maleimides

A series of N-(arylalkyl)maleimides was prepared for the reaction of maleic anhydride and N-(arylalkyl) amines, and their antimicrobial activities were examined. All compounds exhibited antibacterial activity against gram-positive bacteria such as Bacillus subtilis and Staphylococcus aureus. Almost all compounds exhibited antibacterial activity against the gram-negative bacterium, Escherichia coli, but were inactive against Pseudomonas aeruginosa. Activities against gram-positive bacteria were independent of the nature of the substituent on the benzene ring or the length of alkyl group, but that against gram-negative bacteria was influenced by these parameters. All N-(arylalkyl)maleimides showed activity against yeasts and mycelial fungi.     

Synthesis and antifungal activity of imidazole-1-carboxylates

A series of imidazole-1-carboxylates was prepared by reacting various alcohols with trichloromethyl chloroformate and imidazole or N,N'-carbonyl-diimidazole. They were tested for fungitoxic activity in vitro against two phytopathogenic fungi, Botrytis cinerea (grey mould) and Gibberella fujikuroi, and for preventive efficacy against grey mould on cucumber leaves. 1-(4-Substituted phenoxymethyl)-2,2-dimethylpropylimidazole-1-carboxylates showed excellent in-vitro activity against B. cinerea, and moderate activity against G. fujikuroi, and some of them also effectively controlled grey mould in vivo. A 1H-1,2,4-triazole derivative corresponding to an imidazole derivative did not have any activity, while a thiocarboxylate corresponding to an imidazole carboxylate showed excellent activity against both B. cinerea and G. fujikuroi.     

Synthesis and fungicidal activity of N-(p-sulfonylphenyl)-N1 -carbamoylureas

A series of 11 N-(p-sulfonylphenyl)-N¹-carbamoylureas was prepared by reaction of 1,6-diphenyl-2,4-dioxohexahydro-s-triazine with chlorosulfonic acid and thionyl chloride. The resultant N-(p-chlorosulfonylphenyl)-N¹-carbamoylurea was subsequently condensed with amines, butanol, hydrazine and sodium azide. The hydrazide was reacted with carbonyl compounds and the azide with trimethyl phosphite. The products were tested for in-vivo fungicidal activity against barley powdery mildew (Erysiphe graminis); the acetone hydrazone derivative showed the highest activity. © 1998 SCI.     

Photolysis of dichlofluanid

Dichlofluanid was found to be degraded by ultraviolet light in methanol, benzene and acetone solution. The products from acetone solution included N,N-dimethyl-N′-phenylsulphamide, phenyl isocyanate, phenyl isothiocyanate and dimethylamidosulphonyl chloride. G.c.-m.s. studies further indicated the presence of bis(dichlorofluoromethyl) disulphide, 1-(dichlorofluoromethylthio)propan-2-one and 1-(dichlorofluoromethylsulphonyl)propan-2-one. In-vitro tests against Botrytis cinerea showed that irradiation decreased the activity of dichlofluanid and that synergism did not occur.     

Fungitoxicity of 5-aminoisoxazole-4-thiocyanate derivatives

3-Methyl-5-(acyl/alkyl)aminoisoxazole-4-thiocyanates were prepared by rhodanation of N-acyl/alkyl-3-methyl-5-isoxazolamines. These products were tested for antifungal activity against a series of phytopathogenic fungi of different taxonomic classes. Some of the compounds showed interesting in-vitro activity. The more active compound in the in-vitro test displayed a moderate preventive activity against Plasmopara viticola, Alternaria solani and Pyricularia recondita.     

Synthesis and insecticidal and acaricidal activity of new N-(α-substituted phenoxybenzyl)-4-pyrimidinamines

A new class of insecticides and acaricides containing N-(α-substituted phenoxybenzyl)-4-pyrimidinamines as core structure were synthesized and their insecticidal and acaricidal potencies assessed. Among these, both the N-(3 or 4-phenoxybenzyl)-4-pyrimidinamine showed remarkable activity against diamondback moth, Plutella xylostella L., brown rice planthopper, Nilaparvata lugens (Stal) and two-spotted spider mite, Tetranychus urticae Koch. The potency of the new pyrimidinamines was particularly increased when a methyl, ethyl, iso-propyl, or cyclopropyl group was introduced at the α-position of benzyl moiety and it was evident that a single (+) optical isomer is more active than its antipode. Structure-activity relationships are discussed.     

Structural Effects of N-Arylcarbamoylpyrazolines on Calcium Uptake in Rat Brain Synaptosomes

N-Arylcarbamoylpyrazolines with various substituents at the para position of the carbamoyl benzene ring inhibited ATP-dependent Ca²⁺-uptake in synaptosomes prepared from the rat brain. The activity of these compounds was evaluated as log(1/I₅₀), the reciprocal logarithm of half inhibitory concentration, I₅₀ (m ), from the concentration–response curve for the inhibition of Ca²⁺-uptake. Among the compounds tested, methyl 3-(4-chlorophenyl)-4-methyl-1-[N-(4-trifluoromethylphenyl)carbamoyl]-2-pyrazoline-4-carboxylate was the most potent, the I₅₀ value of which as 9·12×10⁻⁷ m . Variations in the activity in terms of log(1/I₅₀) were quantitatively analysed using a substituent parameter, showing that the higher the electron-withdrawing effect of the substituent, the higher was the activity. The substituent effects were similar to those on insecticidal activity against the Americal cockroach. The higher the inhibitory activity against Ca²⁺ uptake, the higher seemed to be the insecticidal activity. Methyl(4S) - 3 - (4 - chlorophenyl) - 4 - methyl - 1 - [N - (4 - chlorophenyl)carbamoyl] - 2 - pyrazoline -4-carboxylate had higher inhibitory activity against Ca²⁺-uptake and higher in-secticidal activity than the R-isomer, but the difference was greater in theCa²⁺-uptake system.     

Stereochemical basis for the insecticidal activity of carbamoylated and acylated pyrazolines

Methyl 3-(4-chlorophenyl)-1-[N-(4-chlorophenyl)carbamoyl]-4-methyl-2-pyrazoline-4-carboxylate was converted to corresponding (1R)- and (1S)-phenethyl esters via its carboxylic acid and acid chloride at the C-4 atom to separate the diastereomers. Their configurations were confirmed by X-ray analysis. Both isomers of the (1R)methylbenzyl ester were subjected to transesterification with sodium methoxide to obtain enantiomers of the starting methyl ester. Their insecticidal activity was measured against American cockroaches (Periplaneta americana (L.)) by injection and against house flies (Musca domestica L.) by topical application under various synergistic conditions with metabolic inhibitors. The activity values of the four α-methylbenzyl esters and the R-isomer of the starting methyl ester were similar. The S-enantiomer of the methyl ester was about 10 and 100 times more active than the R-isomer against the cockroach and the fly, respectively. Some N-arylacetyl and N-aryloxyacetyl derivatives of the starting N-(4-chlorophenyl)carbamoyl compound gave very low activity. Conformation-energy profiles for some compounds suggested that the conformation of substituents on the N-1 atom in the pyrazoline ring has a specific role for the potential insecticidal effects.     

Fungicidal activity of N-(2-cyano-2-methoximinoacetyl)amino acids and their derivatives

More than 20 N-(2-cyano-2-methoximinoacetyl)amino acids and derivatives were synthesised and tested for antifungal activity against grape downy mildew, caused by Plasmopara viticola (de Bary) Berl. & de Toni, and rape downy mildew, Peronospora parasitica Fr. Two of the compounds containing a free carboxylic acid group, a moiety which has been shown to confer phloem mobility on compounds, showed high activity, especially against P. parasitica, in protectant tests. These results indicate that there is no incompatibility between the acid function and fungicidal activity. A number of the esters showed activity comparable with that of cymoxanil in the protectant tests, and the tert-butyl esters of the methionine derivative and its sulfone were more than ten times as active as the commercial compound.     

Recent progress in the field of N-acylalanines as systemic fungicides

The influence of structural variations in compounds of the N-acylalanine type, on their fungicidal activity towards Peronosporales, was examined. Within a series of methyl N-(acyl)-N-(2,6-xylyl)alaninates ( I ), a quantitative structure-activity relationship was given for the curative action against Plasmopara viticola, through a Hansch-type equation. A deviation from this equation is discussed with reference to benalaxyl ( I ; acyl=phenylacetyl). Syntheses and qualitative indications of activity are reported for structural changes in the xylyl and in the alanine moieties. Progress in the latter approach is briefly outlined.     

嘧啶联吡唑甲酰胺类化合物的合成及除草活性

设计合成了一系列结构新颖的嘧啶联吡唑甲酰胺类化合物5a~5o,其结构均经过1H NM R和MS分析确证。初步生物活性测试结果表明:在有效成分150 g/hm2剂量下苗后茎叶喷雾处理时,化合物(R)-N-[1-(4-氯苯基)乙基]-3-二氟甲基-1-(4,6-二甲氧基嘧啶-2-基)-1H-吡唑-4-甲酰胺(5c)、N-[1-(4-氯苯基)乙基]-1-(4,6-二甲氧基嘧啶-2-基)-N-甲基-3-三氟甲基-1H-吡唑-4-甲酰胺(5i)和N-[1-(4-氯苯基)乙基]-1-(4,6-二甲氧基嘧啶-2-基)-3-三氟甲基-1H-吡唑-4-甲酰胺(5k)对繁缕Stellaria media的抑制率高达90%以上;而同样剂量下苗前土壤喷雾处理时,化合物N-[1-(4-氯苯基)乙基]-3-二氟甲基-1-(4,6-二甲氧基嘧啶-2-基)-1H-吡唑-4-甲酰胺(5b)和5c对繁缕的抑制率达100%。该类结构化合物有望作为除草先导化合物进行开发。     

The synthesis and larvicidal activity of N-aroyl-N′-(5-aryl-2-furoyl)ureas

A novel type of diarolyurea compound containing a furan ring has been designed and prepared. Thus, a series of N-aroyl-N′-(5-aryl-2-furoyl)ureas were synthesized by a nucleophilic addition reaction between 5-substituted furamide and aroyl isocyanate in high yield (>80%). Their structures were confirmed by IR, [¹H]NMR and elemental analyses. Bioassay showed that some of them exhibited activity against second-instar larvae of the yellow fever mosquito (Aedes aegypti L.). With the aid of artificial neural network combined with multivariable regression, a preliminary study was made of structure–activity relationship. © 1998 SCI.     

Fungicidal activity of a series of chloroacetylanilidophosphonates

Nine diethyl chloroacetylanilidomethylphosphonates and ten diethyl α-(chloroacetylanilido)benzylphosphonates were prepared by N-chloroacetylation of the corresponding diethyl anilinomethyl- and anilinobenzylphosphonates. These were tested for antifungal activity against six phytopathogenic fungi. Most of the compounds showed moderate protective properties. No significant difference in activity was observed for compounds with an extra aryl ring substituent on the methylene group of the backbone. Compounds with electron-withdrawing substituents, especially chlorine, on the aniline site (R¹) showed higher fungicidal activity than the other compounds with electron-donating groups as substituents.     

The antifungal activity of some sulphonyl derivatives of isoxazole,pyrazole, thiazole and thiophene

Fifty-three heterocyclic sulphonyl derivatives including eight sulphonamides, three sulphonyl azides, nine sulphonohydrazides and twenty sulphonohydrazones of substituted thiophenes, and a smaller range of analogous isoxazoles pryazoles and thiazoles, were tested as potential fungicides in a simple screening procedure against Mucor mucedo, Septoria nodorum, Trichoderma viride, Chaetomium globosum and Aspergillus niger. Several thiophene-2-sulphonyl based compounds exhibited a high level of antifungal activity at 100 mg litre^?1 against the five test species, especially the mono-halogen-substituted sulphonamides and sulphonohydrazines, in which a single chlorine or bromine atom was substituted in the para position of an attached phenyl ring. The most active compound, against all five species of fungus was N-(4-chlorophenyl)-N-(trichloromethylthio) thiophene-2-sulphonamide which had average MIC₅₀ and MIC₁₀₀ values of 86 and 180 μmol respectively. (MIC₅₀ and MIC₁₀₀ values are, respectively, the concentrations required to inhibit fungal growth by 50% and to inhibit it totally.) In general, the isoxazole analogues of the thiophene-2-sulphonyl compounds exhibited a much lower fungitoxic activity, whilst the pyrazole and thiazole based compounds had little or no activity. Compared with the other results, the considerable activity shown by 4-[2′-(3,4-dichlorobenzylidene)hydrazinosulphonyl]thiophene-2-carboxylic acid was unexpected.     

Preparation of some novel phosphonamidates,their phytotoxicity and herbicidal properties

Fourteen new O-phenyl/4-chlorophenyl-N-alkyl/aryl-2-chloroethyl phosphonamidates have been prepared and screened for their phytotoxicity towards monocotyledonous (wheat) and dicotyledonous (mustard) plants and herbicidal activity against wild oat. O-Phenyl-N-propyl-2-chloroethyl phosphonamidate was found to be the most phytotoxic (pre-emergence) and also possessed herbicidal properties. Wheat showed maximum resistance to most of the compounds (post-emergence). N-propyl-4-chlorophenyl-2-chloroethyl phosphonamidate was the least active molecule. © 1998 SCI.     

Insecticidal activity of N,N-diethyl-, N,N-dipropyl-, N,n-di-isopropyl-, and n,n-di-isobutylalkanamides against mosquito larvae

N,N-Diethyl-, N,N-dipropyl-, N,N-di-isopropyl, and N,N-di-isobutylalkanamides in which the acyl moiety ranged from C₈ to C₂₁ were synthesised, and their larvicidal activity was determined against the first-instar larvae of the southern house mosquito Culex quinquefasciatus Say. The four homologous series of amides generally showed an increase in their larvicidal activity as the carbon number in the acyl moiety of the amides increased, until the activity reached a maximum. Subsequently, an increment of carbon number resulted in declining activity in the higher homologues, until the activity disappeared. N,N-Diethyltetradecanamide, N,N-dipropylundecanamide, N,N-di-isopropylundecanamide, and N,N-di-isobutlynonanamide or -dodecanamide were the most active compounds in their respective homologous series of amides; however, they were less active than their analogous N,N-dimethylalkanamides previously studied.     

Synthesis of 2-amino-6-oxocyclohexenylsulfonamides and their activity against Botrytis cinerea

BACKGROUND: With the objective of exploring the fungicidal activity of 2‐oxocyclohexylsulfonamides (2), a series of novel 2‐amino‐6‐oxocyclohexenylsulfonamides (6 to 23) were synthesised, and their fungicidal activities against Botrytis cinerea Pers. were evaluated in vitro and in vivo. RESULTS: The compounds were characterised by IR, ¹H NMR and elemental analysis. Bioassay results of mycelial growth showed that compounds 6 to 23 had a moderate antifungal activity against B. cinerea. N‐(2‐methylphenyl)‐2‐(2‐methylphenylamino)‐4,4‐dimethyl‐6‐oxocyclohexenylsulfonamide (13) and N‐(2‐chlorophenyl)‐2‐(2‐chlorophenylamino)‐6‐oxocyclohexenylsulfonamide (21) showed best antifungal activities, with EC₅₀ values of 8.05 and 10.56 µg mL^?1 respectively. Commercial fungicide procymidone provided an EC₅₀ value of 0.63 µg mL^?1. The conidial germination assay showed that most of compounds 6 to 23 possessed excellent inhibition of spore germination and germ‐tube elongation of conidia of B. cinerea. For in vivo control of B. cinerea colonising cucumber leaves, the compound N‐cyclohexyl‐2‐(cyclohexylamino)‐4,4‐dimethyl‐6‐oxocyclohexenylsulfonamide (19) showed a better control effect than the commercial fungicide procymidone. CONCLUSION: The present work demonstrated that 2‐amino‐6‐oxocyclohexenylsulfonamides can be used as possible new lead compounds for further developing novel fungicides against B. cinerea. Copyright © 2011 Society of Chemical Industry     

新型N-芳基-2-((5-((4,6-二甲基嘧啶-2-基)硫甲基)-1,3,4-噻二唑-2-基)硫)乙酰胺类化合物的合成及杀菌活性

为寻找新型杂环活性化合物,通过活性亚结构拼接,以硫脲和乙酰丙酮为起始原料合成4,6-二甲基嘧啶-2-硫醇,随后经酯化、肼化、环化和缩合反应,设计并采用微波辅助合成了10个新型N-芳基-2-（（5-（（4,6-二甲基嘧啶-2-基）硫甲基）-1,3,4-噻二唑-2-基）硫）乙酰胺类化合物,其结构通过核磁共振氢谱和碳谱、红外光谱、质谱及元素分析确认。初步生物活性测试结果表明,在50 mg/L下,大部分目标化合物对植物病原真菌具有一定的抑制活性,其中化合物8h对黄瓜炭疽病菌Colletotrichum orbiculare的抑制率达77.3%。     

Synthesis of benzylaminopyrimidines and their fungicidal activities against wheat brown rust and barley powdery mildew

Members of a new class of fungicide containing benzylaminopyrimidine as a core structure were synthesized and their fungicidal potencies against wheat brown rust, Puccinia recondita, and barley powdery mildew, Erysiphe graminis, were assessed. Among these fungicides, N-(fluoroalkoxy or fluorophenoxybenzyl)-4-pyrimidinamines showed notable preventive activities. The potency of the new pyrimidines was increased when a difluoromethoxy or tetrafluorophenoxy group was introduced at the 4- or 3-position of the phenyl moiety and a methyl or ethyl group was introduced at the benzyl position. Structure–activity relationships are discussed. © 1998 Society of Chemical Industry     

新型含吡唑杂环邻氨基苯甲酰胺类化合物的合成与杀螨活性

以氯虫苯甲酰胺和氟虫腈的结构为基础,通过活性亚结构拼接的方法,设计合成了24个新型含吡唑杂环邻氨基苯甲酰胺类化合物,其结构经1H NM R、IR及APCI-M S表征。初步生物活性测试结果表明:化合物5-溴-N-[4-氯-2-甲基-6-(甲氨基甲酰基)苯基]-1-1-[2,6-二氯-4-(三氟甲基)苯基]-4-三氟甲基亚磺酰基-1H-吡唑-3-甲酰胺(5k)和5-溴-N-[4-溴-2-甲基-6-(甲氨基甲酰基)苯基]-1-[2,6-二氯-4-(三氟甲基)苯基]-4-三氟甲基亚磺酰基-1H-吡唑-3-甲酰胺(5l)在500 mg/L下对朱砂叶螨Tetranychus cinnabarinus的致死率为100%,但在100 mg/L下其致死率则分别降至30%和50%。所得结果可为邻氨基苯甲酰胺类化合物构效关系研究提供参考。