Quantitative structure-activity study of insecticidal 2-methoxy-5-(substituted-phenyl)-1, 3, 2-oxazaphospholidine 2-sulfides against Musca domestica L. by topical application

The quantitative relationship between the structure of 2-methoxy-5-(substituted-phenyl)-1, 3, 2-oxazaphospholidine 2-sulfides (5-PMOS) and their insecticidal activity against the house fly. Musca domestica L., was analyzed using reported physicochemical parameters and regression analysis. The electronic nature of the substituent on the phenyl group of 5-PMOS has the most significant effect on the activity, followed by hydrophobic and steric effects; the optimum value of Σρ is zero and the more hydrophobic the substituents on the phenyl group, the higher the insecticidal activity. The plots of observed pLD₅₀, values against calculated pLD₅₀ values for compounds having substituents in the ortho-position deviated downwards from those of compounds having substituents at the meta and/or para positions. This ortho-effect, which reduces the insecticidal activity of compounds having substituents at the ortho-position, was expressed by a dummy parameter D, which has the value 2 for di-ortho-substituted derivatives, 1 for mono-ortho-substituted derivatives and zero for others. Thus, the highest activity was obtained for 2-methoxy-5-phenyl-1, 3, 2-oxazaphospholidine 2-sulfide, and the activity was decreased by the introduction of any substituents on the phenyl group.     

Synthesis,fungicidal activity and structure-activity relationships of a series of 1-(3-pyridyl)-1-substituted-but-3-yn-1-ols

A series of 1-(3-pyridyl)-1-substituted-but-3-yn-1-ols and some related compounds were synthesised and tested for antifungal activity against eight phytopathogenic fungi of different taxonomic classes. High activity was shown in particular against Sphaerotheca fuliginea on Cucumis sativus. The compounds containing aromatic substituents gave the best results, not only in protectant but also in systemic and eradicant tests. The quantitative structure-activity relationship suggests that steric effects play an important role in determining fungicidal activity.     

Synthesis and insecticidal activity of 3-(haloalkyl-1,3-dienyl)-2,2-dimethylcyclopropanecarboxylates

New 2,2-dimethylcyclopropanecarboxylic acids bearing halogenated 1,3-alkadienyl substituents at position 3 of the cyclopropane ring were synthesised and the insecticidial activities of their 3-phenoxybenzyl and α-cyano-3-phenoxybenzyl esters against housefly (Musca domestica), Colorado potato beetle (Leptinotarsa decemlineata) and Egyptian cotton leafworm (Spodoptera littoralis) were determined. The activity of these compounds varied according to the relative position of the halogen substituents on the diene chain. The observed changes of activity with the structure of the side chain are discussed in terms of the coplanarity of the conjugated double bonds.     

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.     

Fungicidal activity of 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinones and related compounds

The fungicidal activity of a series of 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinones and their acetates has been assessed against various fungi in vitro and against others, notably powdery mildews, in vivo, and the activity compared with that of analogous compounds bearing saturated side chains. Several of the compounds demonstrated a broad spectrum of activity in vitro. Whereas the presence of α-unsaturation in the side chain is essential for the in-vitro activity against the non-obligate fungi tested, it is of virtually no importance for the curative effect against Erysiphe graminis on barley. Only the corresponding acetates had activity against the latter pathogen.     

Quantitative structure-activity analysis of larvicidal 1-(substituted benzoyl)-2-benzoyl-1-tert-butylhydrazines against Chilo suppressalis

The larvicidal activity of a number of 1-(substituted benzoyl)-2-benzoyl–1 -ten-butylhydrazines against the rice stem borer (Chilo suppressalis Walk.) was measured. Variations in the activity were examined quantitatively using physico-chemical substituent and molecular parameters and regression analysis. The results indicated that the molecular hydrophobicity and the electron-withdrawing inductive/ field effect of ontho substituents are favourable to larvicidal activity. The bulkiness of substituents at the meta and para positions was unfavourable to activity, substitution at the para position being more unfavourable than that at the meta position in terms of van der Waals' volume. The 2,3–, 2,5- and 2,6-disubstitution patterns were also unfavourable to activity. Reductions in larvicidal activity caused by the 2,6-,- 2,3,5- and 2,3,4,5-substitutions were greater than those induced by the 2,3- and 2,5-disubstitutions. When the sum of contributions from favourable effects is greater than that from unfavourable effects, the larvicidal activity is expected to be superior to that of the unsubstituted compound.     

Insecticidal activity of the pyrethrins and related compounds X 5-benzyl-3-furylmethyl 2,2-dimethyicyclopropanecarboxylates with ethylenic substituents at position 3 on the cyclopropane ring

The insecticidal activities against houseflies (Musca domestica L.) and mustard beetles (Phaedon cochleariae Fab.) of the chrysanthemate bioresmethrin, and of 31 related 5-benzyl-3-furylmethyl 2,2-dimethylcyclopropanecarboxylates with alkenyl, alkadienyl or alkoxycarbonylalkenyl substituents at position 3 of the cyclopropane ring are compared to determine the relative influence of the isobutenyl sidechain (as in chrysanthemates) and of the other side chains. Several substituents, in particular (E)- or (Z)-butadienyl or -pentadienyl, give considerably greater activity than isobutenyl but alkoxycarbonyl compounds are less potent.     

Quantitative structure–activity studies of insect growth regulators: XVI. Substituent effects of dibenzoylhydrazines on the insecticidal activity to Colorado potato beetle Leptinotarsa decemlineata

Insecticidal activity against the Colorado potato beetle, Leptinotarsa decemlineata, was measured for a series of substituted N-tert-butyl-dibenzoylhydrazines, in which one of the benzoyl moieties closer to the tert-butyl group was fixed as being 2-chloro-substitued and the other variously substituted singly or doubly. The effects of substituents on the activity were quantitatively analysed using the classical quantitative structure–activity relationship (QSAR) procedure. The activity against the Colorado potato beetle increases with the molecular hydrophobicity. In addition, various types of steric effect are at work, depending upon the positions. Hydrogen-bonding acceptor substituents at the para position enhance the activity. There seem to be threshold (or optimum) values, albeit position-dependent, in the molecular hydrophobicity, above which the activity starts to decrease. This biphasic contribution of the molecular hydrophobicity to activity against coleopterous larvae is the most conspicuous difference in substituent effects from those found for similar compounds against lepidopterous pest insects, and may be the basis of the variations in the activity spectrum for certain compounds in this series. The introduction of bulkier substituents into the meta- and para-positions of the benzene ring, apart from the tert-butyl group, is unfavorable to activity. LD₅₀ values against Colorado potato beetle larvae of methoxyfenozide (RH-2485) and tebufenozide (RH-5992) were in the order of 10⁻⁷ mol per insect, whereas those of RH-5849, and halofenozide (RH-0345) were very low, 10⁻⁹–10⁻¹⁰ mol per insect being selective to the coleopterous larvae. © 1999 Society of Chemical Industry     

Insecticidal activity of the pyrethrins and related compounds. IX. 5-benzyl-3-furylmethyl 2,2-dimethylcyciopropanecarboxylates with non-ethylenic substituents at position 3 on the cyclopropane ring

The insecticidal activities against houseflies (Musca domestica L.) and mustard beetles (Phaedon cochleariae Fab.) of 29 new 5-benzyl-3-furylmethyl 2,2-dimethyl-cyclopropane-carboxylates are compared with those of the corresponding chrysanthe-mate (bioresmethrin) to assess the influence of non-ethylenic and isobutenyl substituents at position 3 of the cyclopropane ring. Of the new groups investigated, only 3-methoxyiminomethyl gives equal or enhanced activity; 3-(2-furyl) esters are moderately effective, but 3-phenyl and 3-alkoxycarbonyl compounds show weak activity. A 3-(2,2,2-trihaloethyl) compound was more active than compounds with other saturated groups, such as isobutyl.     

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 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     

Synthesis and Insecticidal Activity of Some New 3-[4(3H)-Quinazolinone-2-(yl)thiomethyl]-1,2,4- triazole-5-thiols

A series of 14 new 3-[4(3H)-quinazolinone-2-(yl)thiomethyl]-1,2,4-triazoles were prepared and characterized by elemental analyses, IR, [¹H] NMR and mass spectral data. Four of the compounds showed insecticidal activity equivalent to that of malathion against the adult stage of the blow fly (Chrysomyia albiceps). However, their activity against the larval stages of this insect species was considerably weaker.     

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.     

Synthesis and insecticidal/acaricidal activity of novel 3‐(2,4,6‐trisubstituted phenyl)uracil derivatives

A series of novel 3‐(2,4,6‐trisubstituted phenyl)uracil derivatives has been synthesised and assayed for insecticidal/acaricidal activity. The assay indicated certain requirements for optimal insecticidal activity, which can be summarised as follows: (a) the substituents on the phenyl ring should possess hydrophobicity and electron‐withdrawing properties, and the sum of their volumes determines the level of activity; (b) the substituent at the 6‐position on the uracil ring should also possess electron‐withdrawing properties and hydrophobicity, together with the correct volume; (c) the 1‐position on the uracil ring should be unsubstituted for activity against Nephotettix cincticeps and Epilachna vigintioctopunctata, but substituents with length C3 to C4 may be optimal for activity against Tetranychus urticae; (d) certain substituents at the 5‐position of the uracil ring give activity against E vigintioctopunctata and T urticae, but not against N cincticeps; (e) a thiocarbonyl group at the 2‐position of the uracil ring is less effective than a carbonyl group. Of the compounds assayed, 3‐(2,6‐dichloro‐4‐trifluoromethylphenyl)‐6‐trifluoromethyluracil showed high activity against all the species assayed. © 2000 Society of Chemical Industry     

Insect growth regulating activity of 1,5-disubstituted imidazoles against Bombyx mori and Oncopeltus fasciatus

Seventeen 1,5-disubstituted imidazoles possessing a variety of substituents were tested on Bombyx mori and Oncopeltus fasciatus. All compounds induced precocious metamorphosis from 4th-instar larvae of B. mori. Of the compounds tested, 1-benzyl-5-[(E)-2,6-dimethyl-1,5-heptadienyl]imidazole (KK-42) was the most active against B. mori larvae. However, none of the compounds induced precocious metamorphosis in O. fasciatus nymphs, although several showed delayed toxicity. Treated nymphs died during or immediately after the moult. A series of 1-isobutylimidazoles exhibited high activity against O. fasciatus, whereas KK-42 was inactive even at high doses. There was no apparent correlation between the ability of imidazoles to cause precocious metamorphosis in B. mori and the delayed toxicity for O. fasciatus.     

1-(3-氯吡啶-2-基)-5-二氟甲基-1H-4-吡唑酰胺类化合物的合成及杀菌活性

以2,3-二氯吡啶(1)为起始原料,经肼基化、环合、水解和酰氯化反应,生成1-(3-氯-2-吡啶)-5-二氟甲基-1H-吡唑-4-甲酰氯(6),(6)与取代基苯胺(7) 反应,制得13个未见文献报道的1-吡啶基吡唑酰胺类目标化合物。利用核磁共振氢谱、质谱(LC-MS)和元素分析对目标化合物的结构进行了表征。初步杀菌活性测定结果表明,在 50 mg/L下,大部分目标化合物对瓜类炭疽病菌Gibberella zeae、瓜类灰霉病菌Botrytis cinerea和水稻纹枯病菌Rhizoctonia solani的抑制活性均不高,仅ZJ-10对瓜类灰霉病菌的抑制率达76.03%。     

2-anilino-3-methylbutyrates and 2-(isoindolin-2-yl)-3-methylbutyrates,two novel groups of synthetic pyrethroid esters not containing a cyclopropane ring

A new series of substituted 2-anilino-3-methylbutyrates has been prepared; bioassay data for these compounds on Heliothis virescens, Musca domestica, Aphis fabae and Tetranychus urticae are presented and discussed. Some unexpected relationships were observed between the nature of the substituents and the biological activity. Increases in foliar stability were noted with certain substitution patterns. Both α-cyano-3-phenoxybenzyl 3-methyl-2-(α, α, α,2-tetrafluoro-p-toluidino)butyrate and the corresponding 2-(2-chloro-α, α, α-trifluoro-p-toluidino)-3-methylbutyrate showed good stability in air and light, and exhibited biological activities of a similar nature and potency to those of previously known synthetic pyrethroids. Esters of the (R)-2- anilino-3-methylbutyric acids are far more active than those prepared from the (S)-enantiomers. The (R)-configuration at C-2 in these acids is sterically equivalent to the active absolute configuration at the chiral carbon α to the carboxylate group in both the permethrin and the fenvalerate types of pyrethroids. A new class of insecticidal 2-(isoindolin-2-yl)alkanoates is also reported. In this series the most biologically active analogue was α-cyano-3-phenoxybenzyl 3-methyl-2-(4,5,6,7-tetrafluoroisoindolin-2-yl)butyrate. These esters were considerably less stable than the anilino analogues on exposure to air and light.     

Synthesis of some acetylenic and halovinyl heterocyclic carbonyl compounds and their activity against some phytopathogenic fungi

Twenty-three acetylenic or halovinyl carbonyl compounds with heterocyclic substituents were synthesised and tested in vivo against eight phytopathogenic fungi of different taxonomic classes. Some of them were fungicidal against Uromyces appendiculatus on Phaseolus vulgaris, though none showed a wide spectrum of activity.     

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.     

新型含苯并咪唑的(S,S)-2,8-二氮杂双环[4.3.0]壬烷类衍生物的合成及生物活性

通过N-烷基化反应合成了一系列新型含苯并咪唑的(S,S)-2,8-二氮杂双环[4.3.0]壬烷类衍生物,中间体化合物通过环化反应和酰化反应合成得到。所有新型化合物的结构均通过熔点测定、核磁共振氢谱和高分辨质谱确认。生物活性测试结果显示,目标化合物拥有中等的抗植物真菌活性,对东方粘虫Mythimna separata Walker和蚊幼虫Culex pipiens pallens具有中等到良好的杀虫活性。其中化合物6e和6f对油菜菌核Sclerotinia sclerotiorum、马铃薯晚疫Phytophthora infestans、小麦赤霉Fusarium graminearum等真菌具有良好的抗菌活性。化合物6e和6k在200mg/L下对东方粘虫的致死率为100%,化合物6h和6k在2mg/L下对蚊幼虫的致死率为75%。