- Studies on chiral thiophosphoric acids and their derivatives 14. The asymmetric cyclization of (+)-cis-1,2,2-trimethyl-1,3-diaminocyclopentane with thiophosphorodichloridates and o-(4-nitrophenyl)thiophosphorochloridates
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The cyclization of (+)-cis-1,2,2-trimethyl-1,3-diaminocyclopentane 1 with thiophosphorodichloridates 2 or O-(4-nitrophenyl)thiophosphorochloridates 4 forms (+)-2,4,5-diazaphosphabicyclo[3.2.1]octane 3 and 3′, respectively, but the stereoselectivity arising from the condensation of (+)-1 with 4 is less than that of (+)-1 with 2. The distinction between the two product distributions might be due to the significance of different mechanistic routes. In the light of a trigonal bipyramid (TBP) intermediate and Berry pseudorotation (BPR) concept their mechanism are discussed.
- Tang, Chu-Chi,Lang, Hui-Fang,He, Zheng-Jie,Chen, Ru-Yu
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- Generation of ethyl metathiophosphate by thermal fragmentation of O-ethyl N-substituted phosphoramidothioates
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O-Ethyl N-1-adamantylphosphoramidothioate was synthesized and found to fragment on heating in inert solvents to form the pyrophosphate AdNHP(S)(OEt)OP(S)(OEt)OH. The proposed mechanism involves an elimination of the amine portion with release of ethyl metathiophosphate (EtOP(S)O), as was confirmed in previous work for the comparable structure with oxygen. This transient compound then phosphorylates the starting phosphoramidothioate. O-Ethyl N,N-diethylphosphoramidothioate was also synthesized, and while it gave a similar pyro compound on heating, the reaction mixture was more complex. Both phosphoramidothioates, however, served effectively as thiophosphorylating agents toward alcohols, a silanol, and the silanol groups on the surface of silica gel. Exploratory experiments showed that these phosphoramidothioates also could thiophosphorylate the OH group of a monoester of phosphoric acid, as well as that of phosphinic acids, forming anhydrides with the partial structure.
- Quin, Louis D.,Hermann, Petr,Jankowski, Stefan
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- Preparation methods of methyl ethyl thiophosphoryl chloride and methyl ethyl chlorpyrifos
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The invention provides a preparation method of methyl ethyl thiophosphoryl chloride and relates to the field of chemical synthesis. Thiophosphoryl chloride is adopted as an initial raw material and reacts with ethyl alcohol to obtain an intermediate A; the intermediate A reacts with sodium methoxide to obtain the methyl ethyl thiophosphoryl chloride. The preparation method is simple to operate, raw materials are easy to obtain, reaction conditions are mild, and the methyl ethyl thiophosphoryl chloride can be obtained with high efficiency and high yield only through the simple two-step reaction. The invention further provides a preparation method of methyl ethyl chlorpyrifos; the methyl ethyl thiophosphoryl chloride is prepared by adopting the preparation method of the methyl ethyl thiophosphoryl chloride and then reacts with sodium trichloro pyridinol to obtain the methyl ethyl chlorpyrifos. The preparation method is simple and convenient to operate and low in requirements for equipment and can realize the scale production of the methyl ethyl chlorpyrifos.
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Paragraph 0045-0048; 0056-0059; 0067-0070
(2019/03/06)
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- Organophosphorus hapten, wide-spectrum polyspecific antigen, antibody and preparation method and application of hapten, antigen and antibody
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The invention discloses an organophosphorus hapten, a wide-spectrum polyspecific antigen, an antibody and a preparation method and application of the hapten, the antigen and the antibody. The technical defect of an existing organophosphorus pesticide residue immunity analysis method is overcome, the organophosphorus wide-spectrum polyspecific immunity analysis concept is provided, and for organophosphorus pesticides, the method is good in accuracy and sensitivity, can be used for detecting organophosphorus in agricultural products and food samples, realizes universal wide-spectrum polyspecific detection and is quite convenient and rapid to implement in actual use. The wide-spectrum polyspecific antigen has the structure shown in the formula (III) (the formula is shown in the description).
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Paragraph 0058
(2017/12/06)
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- Preparation and activity study of a new organophosphate insecticidals
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A new organophosphorus pesticide, compound 2 was prepared. The laboratory evaluations against Plutella xylostella L larva was performed. This compound showed the similar toxicity with corresponding pesticides but with higher insecticidal activity.
- Yang, Chunhua,Sun, Dequn
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scheme or table
p. 5401 - 5402
(2012/10/18)
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- Distribution and degradation of 14C-ethyl prothiofos in a potato plant and the effect of processing
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Prothiofos and some of its degradation products have been synthesized in our laboratory for investigation purposes. The residual fate of 14C-ethyl prothiofos in different parts of potato plant was studied. The highest level of insecticide residues was detected in and on the leaves of potato plants. The residues of prothiofos insecticide were mainly located in the peels of potato tubers (peeling process removed 85% of the total residue after one month of the treatment), small amount penetrated into the pulp of potato tubers. The degradation products in the extracts of both peel and pulp of potato tubers were identified as prothiofos, prothiofos oxon, desethyl prothiofos, O-ethyl-S-propyl phosphorodithioate, O-ethyl phosphorothioate, O-ethyl-S-propyl phosphoric acid, O-ethyl phosphoric acid, despropylthio prothiofos, and prothiofos oxon sulfoxide. In addition 2,4-dichlorophenol was identified as such and in conjugated metabolites. Potatoes are processed in three ways: frying, boiling, and baking, which is simulated in home preparation. The amount of prothiofos residues was found to decrease on boiling (70%) and further on baking (82%) and frying (100%). The results indicated that frying process is the most effective method for reducing the amount of pesticide residues. Detectable residues were found in boiled potatoes (2.64 ppm), in the boiling water (0.24 ppm), and in the frying oil (0.71 ppm). From these results we concluded that the processed potatoes are safely used for human consumption. Copyright Taylor & Francis Group, LLC.
- Abdel-Gawad,Afifi,Abdel-Hameed,Hegazi
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experimental part
p. 2734 - 2751
(2009/09/06)
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- Synthesis of novel chiral 2-Oxo- And 2-thio-1,3,2-oxazaphospholidines via asymmetric cyclization of L-methionol with (thio)phosphoryl dichlorides
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In order to search for novel antitumor and antiviral agents with high activity and low toxicity, a series of chiral 2-thio(oxo)-1,3,2- oxazaphospholidines were synthesized via the reaction of L-methionol with all kinds of (thio)phosphoryl dichlorides in THF in the presence of triethylamine at room temperature. The structures of all of the new compounds were confirmed by elemental analyses, 1H, 31P NMR, and 1R spectra.
- Liu, Ling-Yan,Chen, Ru-Yu,Huang, You
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- Synthesis and QSAR of O,O-diaryl O-ethyl phosphorothionates for their fungicidal activity against Rhizoctonia solani and Sclerotium rolfsii
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A series of twenty-one O,O-diaryl O-ethyl phosphorothionates having different substituents in the phenyl ring have been synthesized, characterized by various spectroscopic techniques and tested in vitro for fungicidal activity against Rhizoctonia solani and Sclerotium rolfsii. Among these, O,O-di(2,4-dimethylphenyl) O-ethyl phosphorothionates exhibit highest fungicidal activity (ED50 =0.066 mg mL-1, R. solani and 0.042 mg mL-1, S. rolfsii) The quantitative structure activity relationship (QSAR) obtained by means of multiple regression analysis technique using the fungicidal activity data and physico-chemical parameters of benzene ring substituents reveal that the size and shape of ortho-substituents expressed in terms of STERIMOL L and B1 parameters i.e, high value of length parameter, [ΣL(o)] and low value of width parameter, [ΣB1(o)] favour high fungicidal activity against both fungi.
- Lakshman A., Bijul,Gupta
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p. 152 - 157
(2007/10/03)
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- Synthesis of chiral 2-oxo- and 2-thio-1,3,2-oxazaphospho-lidines via the asymmetric cyclization of l-serinoates with (thio)phosphoryl dichlorides
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In this paper is described the asymmetric cyclization of L-serine derivatives with phosphoro(no-)dichloridates or their thio-analogues, and investigated the asymmetric induction effect of chiral carbon centre on the forming chiral phosphorus centre. Some cyclization products have been separated as a pure diastereomer and their configuration is preliminarily discussed.
- He, Zheng-Jie,Chen, Wen-Bin,Zhou, Zheng-Hong,Tang, Chu-Chi
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p. 3473 - 3479
(2007/10/03)
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- Studies on chiral thiophosphoric acids and their derivatives 16. - The asymmetric cyclization of L-(+)-prolinol with (thio)phosphoro(-no)dichloridates
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The cyclizations of L-(+)-prolinol 5 with (thio)phosphoro(-no)dichloridates 6 give 1,2,3-azaphosphaoxabicyclo[3.3.0]octanes 7 consisting of unequal amounts of diastereoisomers, eight pairs of which have been successfully resolved by silica gel column chromatography or recrystallization. The influences of reaction temperature, solvent and substrate concentration upon the asymmetric induction have also been investigated.
- He, Zheng-Jie,Wang, You-Ming,Tang, Chu-Chi
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