Synthesis and Herbicidal Activity of Derivatives of Toxin III from Phoma herbarbum

[Objective] In order to improve the herbicidal activity of toxins III（methyl2-methyl-3,5-dinitrobenzoate） from Phoma herbarbum, its structure was optimized by derivatization. [Method] Sixteen novel title compounds were synthesized by nitration and acylation with o-toluic acid as a starting material. Their structures were confirmed by IR and1 H NMR. [Result] The herbicidal activity screening showed that the inhibition rate of J-L-59 against E. crusgalli roots was 93.7% at 100 μg/ml. The fresh weight efficacy of J-L-59 against A. theophrasti and A. retroflexus was 100%at 1 000 g a.i./hm^2 , and the ED50 value for A. retroflexus was 94.06 g a.i./hm^2 .[Conclusion] J-L-59 has higher herbicidal activity.

Synthesis and Herbicidal Activity of Novel Sulfonylureas Containing Thiadiazol Moiety

Thirteen novel sulfonylureas containing thiadiazole moiety were synthesized in a two-step reaction. Their structures were determined using IR, ^1H NMR, HRFTMS, and elemental analysis. Herbicidal activities of these compounds were determined in the green house bio-assay. The results show that four compounds among them exhibit some activity toward four tested herbs.

Synthesis and Herbicidal Activity of Novel 5-Substituted Benzenesulfonylureas

Sulfonylurea herbicides have been widely used because of their low application rates, good crop sdeetivities and low mammalian toxicities. However, some sulfonylureas might persist unfavourably in the environment with residual problems. In order to look for ecologically safer and environmentally benign sulfonylureas, and on keeping the pyrimidine ring being monosubstitated, 15 novd C5-monosubstituted benzenesulfonylurea compounds were synthesized. The structures of all the compounds synthesized were confirmed by demental analysis and ^1H NMR. Preliminary herbicidal activities of these new sulfonylurea compounds were determined by ALS screening （ in vitro） and pot bioassay experiments（ in vivo）. The herbicidal results show that some novel sulfonylureas are comparable to commercial Foramsulfuron and Monosulfuron.

Novel Synthesis,Crystal Structure and Herbicidal Activity of(3R,4R)-4,7,7-Trimethyl-6-oxabicyclo[3.2.1]octane-3,4-diol

The title compound, （3R,4R）-4,7,7-trimethyl-6-oxabicyclo[3.2.1]octane-3,4-diol （Cl0HlsO3）, has been synthesized by using one-step catalytic synthetic method from a-pinene and structurally characterized by means of IR, JH-NMR, J3C-NMR, HRMS and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/n with a = 7.277（4）, b = 18.177（11）, c = 7.939（5） A, β = 91.122（8）°, Z = 4, V = 1049.9（11） A, Dc = 1.178 g/cm3, Mr = 186.24, λ（MoKa） = 0.71073 A, μ = 0.09 mm^-1, F（000） = 408, R = 0.051 and wR = 0.144. The title complex molecules contained two hydroxyls and are connected through hydrogen bonds to generate a two-dimensional network. Especially, the preliminary herbicidal activity results show that the title compound exhibits herbicidal activity against rape （Brassica campestris） and barnyard grass （Echinochloa crusgalli）.

Synthesis and Herbicidal Activity of Novel Sulfonylurea Derivatives

Sulfonylurea herbicides have been applied worldwide in agriculture. Some sulfonylurea residues might exist in soil longer than that people expected. However, flupyrsulfuron-methyl-sodium which was firstly reported as a new 5-substituted sulfonylurea herbicide has less than one month residual life. Therefore, 5-substituted benzenesulfonylureas are potential molecules to regulate its residual situation. In order to develop new sulfonylurea derivatives, the substituent on the critical 5-posotion of the benzene ring was optimized. On the basis of our former work on sulfonylureas which contains a characteristic mono-substituted pyrimidine moiety, twenty-six new sulfonylurea deriva- tives were synthesized and their structures were confirmed by 1H NMR, 31p NMR and elemental analysis. The greenhouse bioassay tests show that some title compounds exhibit potent herbicidal activity.

Synthesis,Crystal Structure and Herbicidal Activity of N-(4-Methylbenzyl)-4-(3-fluorophenyl)-4-piperidinol Hydrochloride

A novel compound N-（4-methylbenzyl）-4-（3-fluorophenyl）-4-piperidinol hydrochloride has been synthesized and its structure （C19H23ClFNO, Mr = 335.83） was characterized by elemental analysis, IR, ^1H NMR, MS and single-crystal X-ray diffraction analyses. The crystal belongs to the triclinic system, space group P1 with a = 7.2163（6）, b = 10.7905（9）, c = 12.2651（10） A, α = 109.576（2）,β = 98.407（2）,γ= 95.956（2）°, V= 878.14（13）A3, Z = 2, Dc = 1.270 g/cm^3,μ = 0.231 mm^-1, F（000） = 356, S = 1.100, the final R = 0.0525 and wR = 0.1425 for 3206 unique reflections （Rint = 0.0140） with 2736 observed ones （I 〉 2σ（I））. The piperidine ring exhibits a chair conformation. The dihedral angle made by the methyl- and fluoro-substituted benzene rings is 66.84（7）°. There are some intra- and intermolecular hydrogen bonding interactions among the molecules, which stabilize the whole crystal structure. The preliminary biological activity tests indicate good herbicidal activity for the title compound, in particular against the roots of some tested plants （such as Brassica campestris L. and Echinochloa crusgallis L.）.

Synergistic Effects of Several Additives on Herbicidal Activity of Bensulfuron-methyl

[ Objective] The aim was to select the best additives of bensulfuron-methyl. [ Method ] Taking radish as the testing plant, the synergistic effect of five common additives including Span 60, methyl olelate, silicone oil I, Tween 20 and detergent on the herbicidal activities of bensulfuron-methyl were tested in the la- borotory. [ Results ] The effects of the mixture of various additives and bensulfuran-methyl on relative stem control effect of radish, relative inhibition rate against stem length, relative inhibition rote against abeveground fresh weight, relative inhibition rote aginst root length and root fresh weight were studied, and the results showed that Span 60 and methyl olelate had stronger synergistic effect on the herbicidal activities of bensulfuron-methyl, and the synergistic effect of detergent was the weakest. [ Conclusion ] Span 60 and methyl olelate could be used as the synergistic agents of bensulfuron-methyl, and the study could provide references for se- lecting the additives of bensulfuron-methyl.

Synthesis and Herbicidal Activity of Novel Phenoxysulfonylureas Derivatives

Thirteen novel phenoxysulfonylureas derivatives were synthesized, and their structures were confirmed by MS, NMR and element analysis. The herbicidal activity and structure-activity relationship were also investigated. The results of preliminary active tests indicate that the compounds show moderate herbicidal activity.

Crystal Structure and Herbicidal Activity of 5,7-Dimethoxy-(2,4-dichlorophenoxyacetyl- imino)-2H-1,2,4-thiadiazolo[2,3-a]pyrimidine

The title compound 5,7-dimethoxy-(2,4-dichlorophenoxyacetylimino)-2H-1,2,4- thiadiazolo[2,3-a]pyrimidine has been synthesized. In order to investigate the relationship between the structure and herbicidal activity of the target compound, we report its crystal structure and herbi- cidal behavior in the present paper. Crystallographic data: C15H12N4O4Cl2S, Mr = 415.25, mono- clinic, space group P21/n, a = 10.7361(8), b = 11.9610(9), c = 13.0990(10) ?, β = 96.988(2)o, Z = 4, V = 1669.6(2) ?3, Dc = 1.652 g/cm3, F(000) = 848, R = 0.0394, wR = 0.0797 and μ(MoKα) = 0.545 mm-1.

Study on Synthesis and Herbicidal Activity of Heterocyclic Compounds Containing P-P Bond

N,N′-diphenylurea reacted with phosphorus trichloride and phenyl dichlorophosphane giving the heterocyclic compounds 1 and 2 with a direct phosphorus-phosphorus bond (P-P bond), respectively. The new compounds were characterized by elementary analysis, NMR and IR spectra. The results of preliminary bioassay showed that these heterocycles possess selective herbicidal activity at 1.5 kg/hm2.

Synthesis, Crystal Structure and Herbicidal Activity of N-(7-Chloro-5-ethoxy-2H-[1,2,4]thiadiazolo[2,3-a] pyrimidin-2-ylidene)-2-(2,4-dichlorophenoxy)propanamide

The title compound N-（7-chloro-5-ethoxy-2H-[1,2,4]thiadiazolo[2,3-a]pyrimidin- 2-ylidene）- 2-（2,4-dichlorophenoxy）propanamide 3 has been synthesized through using bromine as cyclic reagent in 63% isolated yield. Suitable single crystals for X-ray diffraction were obtained by recrystallization from the mixture solvents at room temperature. Crystallographic data of 3： C 16H13C13O3S, Mr = 447.71, triclinic, space group P1, a = 8.7461（8）, b = 9.9560（10）, c = 11.8572（11） A, a = 94.341（2）, β = 94.683（2）, γ = 112.929（2）°, Z = 2, V= 941.21（15） A^3, Dc = 1.580 g/cm^3, F（000） = 456, R = 0.0794, wR = 0.2056 andμ（MoKa） = 0.623 mm^-1. The title compound 3 was found to be effective in herbicidal activity.

Crystal Structure and Herbicidal Activity of 5,7-Dimethoxy-(2,4-dichlorophenoxyacetyl- imino)-2H-1,2,4-thiadiazolo[2,3-a]pyrimidine

The title compound 5,7-dimethoxy-(2,4-dichlorophenoxyacetylimino)-2H-1,2,4- thiadiazolo[2,3-a]pyrimidine has been synthesized. In order to investigate the relationship between the structure and herbicidal activity of the target compound, we report its crystal structure and herbi- cidal behavior in the present paper. Crystallographic data: C15H12N4O4Cl2S, Mr = 415.25, mono- clinic, space group P21/n, a = 10.7361(8), b = 11.9610(9), c = 13.0990(10) ?, β = 96.988(2)o, Z = 4, V = 1669.6(2) ?3, Dc = 1.652 g/cm3, F(000) = 848, R = 0.0394, wR = 0.0797 and μ(MoKα) = 0.545 mm-1.

Crystal Structure and Herbicidal Activity of N-(5,7-Dimethoxy-2H-[1,2,4]thiadiazolo[2,3-a]pyrimidin-2-ylidene)-2-(2,4-dichlorophenoxy)propanamide

The title compound N-（5,7-dimethoxy-2H-[1,2,4]thiadiazolo[2,3-a]pyrimidin-2- ylidene）-2-（2,4-dichlorophenoxy）propanamide 3 has been synthesized through using bromine as cyclic reagent in 66% isolated yield. Suitable single crystals for X-ray diffraction were obtained by recrystallization from the mixture solvents at room temperature. Crystallographic data of 3： C32H28Ci4N8O9S2, Mr = 874.56, monoclinic, space group P21/c, a = 18.612（8）, b = 14.084（6）, c = 14.757（6） A, α = 90.00, β = 95.505（7）, ）, = 90.00°, Z = 4, V= 3850（3） A^3, Dc = 1.509 g/cm^3, F（000） = 1792, R = 0.0704, wR = 0.1454 and ° = 0.479 mm^-1. The title compound 3 was found to be effective in herbicidal activity.

Synthesis and Herbicidal Activity of 1-Phenoxyacetyl-3-arylimidazolidine-2,4-dione Compounds

In order to find new herbicidal compounds, twelve novel 1-phenoxyacetyl-3-arylimidazolidine-2,4-dione compounds were designed and synthesized by substructure combination strategy using 3-arylimidazolidine-2,4-dione as the intermediate. The structures of the target compounds were confirmed by;H NMR and IR. The preliminary bioassay results showed that most of the target compounds had good inhibition against rape and barnyardgrass at the concentration of 100 mg/L. Especially, compound H3 and H5 showed 100% inhibitory activity against rape.

Herbicidal Activity of 41% Flufenacet SC and Indoor Measurement of Safety to Soybean, Wheat and Maize

[Objective] The paper was to explore the herbicidal activity of 41% flufenacet SC and its safety to soybean, wheat and maize. [Method]The herbicidal activity of 41% flufenacet SC on four species of weeds and its safety to three crops were determined by indoor bioactivity assay.[Result] 41% Flufenacet SC had good control effects against Amaranthus retroflexus, Descurainia Sophia, Bromus japonicus and Echinochloa crusgalli, with the ED90 of 154.1, 204.9, 273.1 and 140.9（a.i.） g/hm2, respectively. [Conclusion] The selectivity index of 41% flufenacet SC between the three crops tested and the two species of weeds was 6.63-9.24. The agent had good safety to soybean, wheat and maize.

Synthesis, Characterization, X-ray Crystal Structure and Herbicidal Activity of(E)-2-(2,4-Dichlorophenoxy)-1-(5,5-dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)vinyl 2-(2,4-Dichlorophenoxy)acetate

A new crystal of（E）-2-（2,4-dichlorophenoxy）-1-（5,5-dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl）vinyl 2-（2,4-dichlorophenoxy）acetate has been determined by single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P1 with a = 7.9393（17）, b = 11.974（3） ？, c = 13.532（3） ？, α = 90.937（4）, β = 101.998（3）, γ = 101.363（4）°, V = 1231.5（5） ？3, Dc = 1.500 Mg/m3, Z = 2, F（000） = 568 and μ = 0.585 mm^（-1）. The molecular packing in the crystal is the result of C（10）–H（10）···O（5） hydrogen bond, as well as weak π-π stacking interactions. The herbicidal activity results indicated that the title compound 3 showed 80~100% inhibitory activities against all of the tested weeds at a dosage of 150 g×ai/ha.

The Herbicidal Activity of Mutant Isolates from Botrytis cinerea

Fifteen mutant isolates were obtained by ultraviolet mutation from parent isolate Botrytis cinerea BC-4. Among them three mutant isolates, BC4-1, BC4-2, and BC4-15, showed strong herbicidal activity. BC4-1 showed maximum herbicidal activity for inhibition of germination and growth of Digitaria sanguinalis L. and Arnaranthus retroflexus L. The results also showed that herbicidal activity was influenced by differing pH of PD media, with pH value of 4.0 being the optimum. The crude toxin was extracted using chloroform, petroleum ether, and ethyl acetate, respectively, and the ethyl acetate extracts showed the strongest inhibitory activity on the germination and growth of D. sanguinalis L. and A. retroflexus L. Using HPLC, one fraction with an absorption peak at 271 nm was separated from the crude toxin. This fraction could strongly inhibit the growth of D. sanguinalis L. at a concentration of 100 mg L^-1 and could completely inhibit the seed germination of D. sanguinalis L. and A. retroflexus L. at a concentration of 50 mg L^-1 .

Synthesis and Herbicidal Activity of 2-Benzoyliminopyrimido[3,2-b]-1 2,4-Thiadiazolines

A series of 2-benzoyliminopyrimido[3,2-b]-1,2,4-thiadiazolines were synthesized and tested for herbicidal effects. All of them are new compounds and their structures were confirmed by (HNMR)-H-1, IR, MS. The preliminary herbicidal tests show that some of the target compounds have potent activity and very good selectivity to rice.

Possible Mechanism Associated with Herbicidal Activity of Soybean Meal Hydrolysate (SMH)

Soybean meal hydrolyzate （SMH） has been proposed for use as a natural preemergence herbicide.However,the mechanism by which SMH exerts its herbicidal activity remains unclear.In this paper,the herbicidal activities of SMH against perennial ryegrass （Lolium perenne L.） under non-sterile and sterile conditions were evaluated and the relationship between the molecular weight of the ultrafiltration （UF） fractions of SMH and their herbicidal activities were investigated.Besides,the ammonia content changes of the media of SMH treatments 7 d after incubation were also analyzed.The results showed that SMH inhibited the radicle growth of germinating L.perenne seeds in a dose-dependent manner under non-sterile condition.However,SMH in the concentrations investigated increased the radicle length and shoot length by 14-17% and 11-15% respectively under sterile condition.The ammonia contents in the SMH media at all treatments increased greatly from less than 0.01 mg L-1 to up to 11.86-41.37 mg L-1 after 7 d incubation under non-sterile condition.However,ammonia content did not change under sterile condition,proposing that the herbicidal activity might be caused by the free ammonia released from SMH by microbial activity.There was no difference on the perennial ryegrass radicle inhibition among the UF fractions of SMH on an equivalent N basis.It could be concluded that SMH exerted its herbicidal activity through the free ammonia released under non-sterile condition instead of by specific peptide（s） in SMH.

Two Novel Dibutyltin Complexes with Trimers and Hexanuclear Based on the Bis(5-Cl/Me-salicylaldehyde) Carbohydrazide: Syntheses, Structures, Fluorescent Properties and Herbicidal Activity

Two novel bis(2-hydroxy-5-R-benzylidene)carbohydrazide dibutyltin complexes(R:Cl(T1),Me(T2))with hexanuclear and triangular frame structures were obtained by microwave-assisted solvothermal reaction of dibutyltin oxide precursor with the ligands in methanol environments,However,their structures are characterized by elemental analysis,IR,(1H,13C)NMR spectra,and the molecular structures of T1 and T2 were confirmed by X-ray diffraction.The crystal of T1 belongs to triclinic system,space group P1,and T2 is of monoclinic system,space group C2/c.Five-coordinated distorted triangular bipyramids and six-coordinated distorted octahedral configurations were formed by the coordination of oxygen and nitrogen atoms of ligands with two dibutyltins,respectively,and trimer hexanuclear dibutyltin complexes were constructed by the cross-coordination of enol imines.The two complexes exhibit fluorescence emission in DMF solvents and DMF-water mixtures.When the volume fraction of water content is between 0 and 10%(V/V),the aggregation fluorescence enhancement effect is good,and fluorescence quenching occurs when the water content is more than 10%(V/V).The T1 can inhibit the growth of target plants,such as Portulaca oleracea,Cassia tora L.,Brassica campestris L.ssp.chinensis var.utilis Tsen et Lee and Amaranthus tricolor L.The T2 can selectively inhibit the growth of Portulaca oleracea L.,Amaranthus spinosus L.and Amaranthus tricolor L.It can be used as a candidate herbicide for Portulaca oleracea L.,Amaranthus spinosus L.and Amaranthus tricolor L.