826990-46-9

The invention relates to synthesis and application of 3-(1-aminoethylene)-6-methylpyran-2, 4- dione derivatives. The structural formula of the derivative is shown in the specification. The structuralgeneral formula of the compound is (I), wherein R and R1

In order to develop a novel herbicide containing the β-triketone motif, a series of 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one derivatives were designed and synthesized. The bioassay results showed that compound II15 had good pre-emergent herbicidal activity even at a dosage of 187.5 g ha-1. Moreover, compound II15 showed a broader spectrum of weed control when compared with a commercial herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), and displayed good crop safety to Triticum aestivum L. and Zea mays Linn. when applied at 375 g ha-1 under pre-emergence conditions, which indicated its great potential as a herbicide. More importantly, studying the molecular mode of action of compound II15 revealed that the novel triketone structure is a proherbicide of its corresponding phenoxyacetic acid auxin herbicide, which has a herbicidal mechanism similar to that of 2,4-D. The present work indicates that the 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one motif may be a potential lead structure for further development of novel auxin-type herbicides.

Among alkylphosphonates Io,O,O-dimethyl 1-(2,4-dichlorophenoxyacetoxy) ethylphosphonate (clacyfos) was found to be an effective inhibitor against dicotyledons PHDc and exhibited excellent herbicidal activity in our previous work. According to our study on the alkylphosphonates Io, both R1 and R2 groups in the structural unit of phosphorus-containing played a very important role in herbicidal activity. Therefore, a series of 2-[1-(substituted phenoxycarboxy)alkyl]-5,5-dimethyl-1,3,2-dioxaphosphinane-2-one containing fluorine II was obtained by the modification of alkylphosphonates Io. The bioassay results showed that cyclic phosphonate II-6 with CH3 as R, 2-Cl,4-F as Yn exhibited promising herbicidal activity. Its herbicidal activity, weed-controlling spectrum, selectivity between crops and weeds were further evaluated in greenhouse and field.

A series of novel 4-[(substituted phenoxyacetoxy)methyl]-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-one 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l, 4m, 4n, 4o were synthesized. Their structures were confirmed by IR,1H NMR, mass spectroscopy, and elemental analyses. The results of preliminary bioassays show that some of the title compounds exhibit moderate to good herbicidal and fungicidal activities. For example, the title compounds 4b, 4c, 4f, 4h, 4i, and 4j possess 90–100% inhibition against the growth of roots of both rape and barnyard grass at 10 mg/L. Moreover, the title compounds 4f, 4g, and 4h possess 75–89% inhibition against Botrytis cinerea at the concentration of 50 mg/L.

(Chemical Equation Presented) A series of novel ethyl 4-(methyl or trifluoromethyl)-2-(2-(substituted phenoxy)acetamido)thiazole-5-carboxylates 7a, 7b, 7c, 7d, 7e and 8f, 8g, 8h, 8i, 8j, 8k, 8l, 8m, 8n, 8o, 8p, 8q, 8r were synthesized, and their structures were confirmed by IR, 1H-NMR, MS spectra and elemental analysis. The results of preliminary bioassays show that some of the title compounds exhibit moderate to good herbicidal activities. Compared with the fluorine free compounds 7a, 7b, and 7e, the compounds bearing fluorine 8g, 8j, and 8q showed higher herbicidal activities with 70-100% inhibition against Capsella bursa-pastoris, Amaranthus restroflexus, and Eclipta prostrata at the dosage of 150 g/ha, which indicated that the trifluoromethyl on the thiazole ring was beneficial for the herbicidal activity. Furthermore, compounds 8f, 8g, 8h, 8i, 8j, 8k, 8l, 8m, 8n, 8o, 8p, 8q, 8r were tested for fungicidal activity against Pseudoperonospora cubensis at 500 μg/mL. Compounds 8f and 8q showed the best fungicidal activity with more than 80% inhibition.

A series of novel O,O-dimethyl 1-(substituted phenoxyacetoxy)-1-(pyridin-2-yl or thien-2-yl)methylphosphonates 6a-n and 7a-d were synthesized. Their structures were confirmed by IR, 1H NMR, mass spectroscopy, and elemental analyses. The results of preliminary bioassays show that some of the title compounds exhibit moderate to good herbicidal and fungicidal activities. For example, the title compounds 6a, 6c, 6l, 6m, and 7d possess 90-100% inhibition against most of the tested plants at the dosage of 1500 g ai/ha, whereas the title compounds 6b, 6g-h and 6n possess 92-100% inhibition against Fusarium oxysporum, Phyricularia grisea, Botrytis cinereapers, Gibberella zeae, Sclerotinia sclerotiorum, and Cercospora beticola at the concentration of 50mg/L.

A series of 2-methylpropan-2-aminium methyl 1-(substituted phenoxyacetoxy) alkylphosphonates were selectively synthesized by reacting the corresponding dimethyl 1-(substitutedphenoxyacetoxy)alkylphosphonates with an excess of 2-methylpropan-2-amine. All the title compounds were identified by IR, 1H NMR, and 31P NMR, some of them were further analyzed by 19F NMR and 13C NMR. Their herbicidal activity was investigated and the results showed that most of the demethylated aminium salts exhibited notable herbicidal activities against Brassica napus L. and Echinochloa crusgalli. Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures and tables.

A series of novel 2-(substituted phenoxyacetoxy)alkyl-5,5-dimethyl-1,3,2- dioxaphosphinan-2-one bearing fluorine 5a-n and fluorine free 5o-q were designed and synthesized. The results of bioassay showed that some of the target compounds exhibited excellent herbicidal activities to Abutilon theophrasti, Brassica juncea, Amaranthus retroflexus and Eclipta prostrata in post-emergence treatment at a dosage of 150 g ai/ha. It could be found that the type and position of fluorine-containing group as X or Y on benzene ring had a very important effect on herbicidal activity. Compound 5l 2-[(2-chloro-4- fluorophenoxy)acetoxy](methyl)methyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one showed notable herbicidal activity, with 100% inhibition against A. theophrasti and A. retroflexus; and compound 5m 2-(3-trifluoromethylphenoxyacetoxy)(methyl) methyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one with 100% inhibition against A. theophrasti even at a dosage of 75 g ai/ha. Additional crop selectivity testing showed that compounds 5g 2-(3-trifluoromethylphenoxyacetoxy)(phenyl)methyl-5,5- dimethyl-1,3,2-dioxaphosphinan-2-one and 5l are safe to rice, corn, cotton, rape and wheat.

On the basis of the previous work for optimization of O,O-diethyl α-(substituted phenoxyacetoxy)alkylphosphonates, further extensive syntheticmodifications were made to the substituents in alkylphosphonate and phenoxymoieties of the title compounds. New O,O-dimethyl α-(substituted phenoxyacetoxy)alkylphosphonates were synthesized as potential inhibitors of pyruvate dehydorogenase complex (PDHc). Their herbicidal activity and efficacy in vitro against PDHc were examined. Some of these compounds exhibited significant herbicidal activity and were demonstrated to be effective inhibitors of PDHc from three different plants. The structure-activity relationships of these compounds including previously reported analogous compoundswere studied by examining their herbicidal activities. Both inhibitory potency against PDHc and herbicidal activity of title compounds could be increased greatly by optimizing substituent groups of the title compounds. O,O-Dimethyl α-(2,4- dichlorophenoxyacetoxy)ethylphosphonate (I-5), which acted as a competitive inhibitor of PDHc with much higher inhibitory potency against PDHc from Pisum sativum and Phaseolus radiatus than from Oryza sativa, was found to be themost effective compound against broadleaf weeds and showed potential utility as herbicide.

To investigate the influence of a fluorine moiety on the biological activity of phenoxyacetoxyalkylphosphonates, a series of fluorine-containing phenoxyacetoxyalkylphosphonates were synthesized and screened for herbicidal activity in a greenhouse. The majority of the title compounds showed better preemergence activity than postemergence activity against the test plants, especially on monocotyledon. Compound 5l exhibited notable activity. Results showed that by introducing a fluorine moiety to the parent structure of phenoxyacetoxyalkylphosphonates, a series of new compounds with satisfactory herbicidal activity could be synthesized. A reasonable combination of a fluorine moiety and other substituents on the benzene ring had a great influence on the herbicidal activity. Copyright Taylor & Francis Group, LLC.

Fluoro-substituted 3-cyano-2-methyl-benzo[b]furans and ethyl 2-methyl-benzo[b]furan-3-carboxylates are conveniently prepared in a single step in good yield by the microwave induced tandem intramolecular Wittig and Claisen rearrangement reactions of the corresponding [(aryloxyacetyl) (cyano) methylene] triphenylphosphorane and [(aryloxyacetyl) (ethoxycarbonyl) methylene] triphenylphosphoranes, respectively. Graphical Abstract