- An efficient protocol for the synthesis of 2-chloroethylphosphonic acid
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An efficient synthetic route to prepare 2-chloroethyl-phosphonic acid (ethephon) with high purity was developed.
- Cauret,Brosse,Derouet,De Livonniere
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- Joint production method of ethephon and vinylphosphonic acid
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The invention discloses a joint production method of ethephon and vinylphosphonic acid. The joint production method comprises the following steps of acylating bis(2-chloroethyl)-2-chloroethyl phosphonate by phosgene or thionyl chloride under the action of a catalyst to obtain a mixture of vinyl phosphonic chloride and 2-chloroethyl phosphonic chloride; separating the vinyl phosphonic chloride from the 2-chloroethyl phosphonic chloride in a reduced pressure distillation mode; hydrolyzing the vinyl phosphonic chloride and the 2-chloroethyl phosphonic chloride to obtain the vinylphosphonic acid and the ethephon. According to the joint production method disclosed by the invention, two products of the ethephon and the vinylphosphonic acid are synthesized by using the bis(2-chloroethyl)-2-chloroethyl phosphonate; a process is simple, and the purities of the two products are improved.
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Paragraph 0015
(2018/02/04)
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- Ethephon by-product 2-chloro ethyl-anhydride conversion into 2-chloro ethyl phosphonic acid method (by machine translation)
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The invention discloses a method for converting an ethephon by-product 2-chloroethyl phosphoric acid anhydride into 2-chloroethyl phosphoric acid. According to the invention, the ethephon by-product 2-chloroethyl phosphoric acid anhydride is completely converted into the 2-chloroethyl phosphoric acid through methods of common hydrolyzation at the temperature of 75 to 100 DEG C and low-boiling point acid catalysis backflow hydrolyzation at the temperature of 85 to 110, so as to enable the mass content of ethephon technical material to be increased to 91 to 96 percent from 82 to 90 percent; through the great increasing of the mass content ethephon technical material, the export market of ethephon products is further expanded. The method provided by the invention is efficient and low in cost, and serves as a new technique, with an industrialization value, for converting the ethephon by-product 2-chloroethyl phosphoric acid anhydride into the 2-chloroethyl phosphoric acid.
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Paragraph 0030-0031
(2017/02/23)
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- Preparation of high quality ethephon using domestic diester bis-(2-chloroethyl)-2-chloroethylphosphonate as substrate
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Ethephon has been widely used globally. However, few companies can manufacture high quality ethephon with content of 90% in China mainland. This work described a practical procedure, which utilizing bis-(2-chloroethyl)-2- chloroethylphosphonate 2 produced by local Chinese companies as substrate to prepare ethephon with content of over 90 % and high yield.
- Zhang, Wenlong,Sun, Dequn
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p. 6463 - 6464
(2013/07/26)
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- Microwave-assisted hydrolysis of phosphonate diesters: An efficient protocol for the preparation of phosphonic acids
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A new highly efficient method for the hydrolysis of acyclic nucleoside phosphonate diesters (or generally of any organophosphonates) to the corresponding phosphonic acids has been developed. This novel methodology employs inexpensive hydrochloric acid in equimolar amounts to the number of ester groups present in the molecule and thus, avoids using trimethylsilyl halogenides, the standard reagents for these types of transformations. Moreover, simple and easy work-up of the reaction mixture affords very clean products in high yields (usually 77-93%). Another advantage of the described hydrolysis of phosphonate diesters is the fact that the course of the reaction can be instantly monitored through pressure changes in the reaction vessel. This 'green' method has also been successfully used for the preparation of otherwise synthetically difficult to access (phosphonomethoxy)ethyl (PME) derivatives of guanine (PMEG) and hypoxanthine (PMEHx), and furthermore, the method gains access to important novel acyclic nucleoside phosphonates derived from 2-chlorohypoxanthine and from xanthine (e.g. PMEX).
- Jansa, Petr,Baszczynski, Ondrej,Prochazkova, Eliska,Dracinsky, Martin,Janeba, Zlatko
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supporting information; experimental part
p. 2282 - 2288
(2012/09/08)
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- Process for making a plant growth regulator
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A method for making a plant growth regulator includes the step of reacting vinyl chloride with a phosphorous reagent.
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Page/Page column 6
(2008/06/13)
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- Comparative study on hydrolysis of 2-chloroethylphosphonic acid dialkylesters
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2-Chloroethylphosphonic acid dialkylesters (bis-(2-chloroethyl), dimethyl, diethyl, dipropyl, dibutyl and dipentylesters) were hydrolyzed in order to obtain 2-chloroethylphosphonic acid, used as a plant growth regulator. Experiments were made in neutral or acid conditions, in order to find optimal conditions for esters hydrolysis. The obtained 2-chloroethylphosphonic acid was tested, regarding its biological activity, on melon, cucumber, blackcurrant and bilberry.
- Ilia, Gheorghe,Cǎprita, Adrian,Iliescu, Smaranda,Popa, Adriana,Pascariu, Aurelia,Bora, Alina,Dehelean, Gheorghe
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p. 501 - 506
(2007/10/03)
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- Patch preparations for treating plants
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The following invention introduces a patch preparation for treating plants, whereas the patch preparations comprise a chemical layer composed of at least one agrochemically active compound, at least one adhesive and optionally, one or more additives. The components are dispersed in a matrix state on a substrate which are then introduced on the roots of the plant to be treated.
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- Optimization of 2-chloroethylphosphonic acid synthesis by acid hydrolysis of dialkyl-2-chloroethylphosphonate compounds. Influence of the nature of alkyl phosphonate functions
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2-Chloroethylphosphonic acid (ethephon) 1 is very much used in agriculture as a plant regulator.It is an especially good stimulant used to increase the latex production of Hevea brasiliensis.Ethephon is generally obtained by HCl hydrolysis of bis(2-chloroethyl)-2-chloroethylphosphonate, previously prepared by Arbuzov rearrangement of tri(2-chloroethyl)phosphite.However, because of the low reactivity of 2-chloroethylphosphonate functions towards acid hydrolysis, this synthetic way is not convenient to prepare pure 2-chloroethylphosphonic acid with high yields.The present purpose was to study the hydrolysis of various dialkyl-2-chloroethylphosphonates in view to define an efficient synthetic protocol, leading to very pure crystallized ethephon with high yields. - Keywords: 2-chloroethylphosphonic acid; ethephon; dialkyl-2-chloroethylphosphonate; Arbuzov reaction; trialkyl phosphite; acid hydrolysis
- Cauret, Laurent,Brosse, Jean-Claude,Derouet, Daniel,Livonniere, Hugues De
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p. 463 - 470
(2007/10/03)
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- Process for the production of aliphatic phosphonic acids
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An improvement in the process for the manufacture of aliphatic phosphonic acid the improvement comprising maintaining the reaction zone volume at about 80 to 95 percent capacity of reactants and/or products by continuously adding diester of aliphatic phosphonic acid reactant up to about 60 percent of the total reaction time said reactant being added in an amount sufficient such that said reactants and/or products will always be present in said reactor so as to occupy at least 80 percent of the reaction zone volume during said reactant addition.
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- Synergistic herbicidal compositions
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Synergistic herbicidal activity is displayed by compositions comprising the following two components: (a) a pyrrolidone of the formula STR1 in which X is selected from the group consisting of hydrogen, chlorine and methyl; Y is selected from the group consisting of hydrogen, chlorine and bromine; Z is selected from the group consisting of chlorine and bromine; R1 is selected from the group consisting of hydrogen and C1 -C4 alkyl; R2 is selected from the group consisting of hydrogen, halogen, C1 -C4 alkyl, acetyl, trifluoromethyl, nitro, cyano, C1 -C4 alkoxy, C1 -C4 alkylthio, C1 -C4 alkylsulfinyl, C1 -C4 alkylsulfonyl, trifluoromethylsulfinyl, trifluoromethylsulfonyl, pentafluoropropionamido, and 3-methylureido; and R3 is selected from the group consisting of hydrogen, C1 -C4 alkyl, chlorine and trifluoromethyl; and (b) a phosphonic acid of the formula STR2 in which R4 is selected from the group consisting of C1 -C4 alkyl, C1 -C4 haloalkyl, and --CH2 NHCH2 COOH, at a weight ratio of (a) to (b) of from about 0.1:1 to about 20:1.
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- Plant growth regulators
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New agents for regulating plant growth, especially for reducing the height of plants, containing a mixture of a quaternary substituted thianium or ammonium salt and a phosphonic acid derivative.
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- ZUR CHEMIE DER 2-HYDROXYETHANPHOSPHONSEAURE
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Acidolysis and hydrolysis of 2-acetoxyethanephosphonic acid dimethyl ester 2 and 2-hydroxyethanephosphonic acid dimethyl ester 3 and their derivatives leads to 2-hydroxyethanephosphonic acid 1.With the aid of 31P-NMR-spectroscopy, the courses of the reactions are investigated and the by-products are identified and determined quantitatively.
- Kleiner, Hanss-Jerg,Schumann, Christian
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p. 363 - 370
(2007/10/02)
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- Preparation of β-haloethylphosphonic acids and half esters thereof
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A process for producing β-haloethylphosphonic acids, by cleaving bis(alkyl or haloalkyl) β-haloethylphosphonate with anhydrous hydrogen halide at a temperature of 140°-175° C.
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- 1,2,3-Thiadiazole-3-in-5-ylidene-urea derivatives, process for making the same and compositions containing the same having growth regulating activity for plants
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1,2,3-Thiadiazole-3-in-5-ylidene-urea derivative of the formula STR1 in which R1 is hydrogen or alkyl which may be substituted in one or several places by oxygen or sulfur and wherein R2 and R3 have the meaning as given in the attached specification and wherein X is oxygen or sulfur. The compounds have properties suited for controlling the natural growth and natural development of plants and in addition have a superior defoliating property without accompanying unpleasant odors.
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- 1,2,3-Thiadiazole-2-id derivatives, process for making the same and composition containing the same having a growth regulating activity for plants
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1,2,3-Thiadiazole-2-id-derivative of the formula STR1 in which R1 is hydrogen or alkyl which may be substituted in one or several places by oxygen or sulfur and wherein R1 has the meaning as given in the attached specification and wherein X is oxygen or sulfur and B is a univalent metal atom. The compounds have properties suited for controlling the natural growth and natural development of plants and in addition have a superior defoliating property.
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- Process for the manufacture of 2-chloroethane-phosphonic acid
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An improved process for the manufacture of 2-chloroethane phosphonic acid in which 2-chloroethane phosphonic acid bis(2-chloroethyl)-ester is heated with excess hydrogen chloride in the presence of 0.1 to 31% by weight of water at temperatures above 100° C under pressure, the 1,2-dichloroethane formed during the reaction is continuously or discontinuously distilled off and the decrease in pressure is compensated by adding gaseous hydrogen chloride.
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- Process for the manufacture of aliphatic phosphonic acids
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An improved process for the manufacture of an aliphatic phosphonic acid, particularly 2-chloroethylphosphonic acid, of the type wherein a diester of the aliphatic phosphonic acid, particularly bis-(2-chloroethyl)-2-chloroethylphosphonate, is reacted with anhydrous hydrogen halide, particularly hydrogen chloride, to produce a reaction product containing the aliphatic phosphonic acid, and the corresponding aliphatic halides particularly ethylene dichloride.
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