16672-87-0

Basic information

• Product Name: Ethephon
• Synonyms: (2-chloroehtyl)phosphonicacid;(2-chloroethyl)-phosphonicaci;2-cepa;2-chloraethyl-phosphonsaeure;2-Chloroethylenephosphonic acid;2-Chloroethylphosphonicaicd;acidechloro-2-ethyl-phosphonique;Amchem 68-250
• CAS NO: 16672-87-0
• Molecular Formula: C₂H₆ClO₃P
• Molecular Weight: 144.49
• EINECS: 240-718-3
• Product Categories: Plant Regulator;Miscellaneous;PLANT GROWTH REGULATOR
• Mol File: 16672-87-0.mol

Chemical Properties

• Melting Point: 70-72 °C(lit.)
• Boiling Point: 265°C(lit.)
• Flash Point: 155.4 °C
• Appearance: White to beige/Powder
• Density: 1.2000
• Vapor Pressure: 2.62E-05mmHg at 25°C
• Storage Temp.: 2-8°C
• PKA: 1.88±0.10(Predicted)
• Water Solubility: Completely soluble in water
• Sensitive: Hygroscopic
• Merck: 14,3732
• BRN: 1751208
• CAS DataBase Reference: Ethephon(CAS DataBase Reference)
• NIST Chemistry Reference: Ethephon(16672-87-0)
• EPA Substance Registry System: Ethephon(16672-87-0)

Safety Data

• Hazard Codes: C
• Statements: 20/21-34-52/53
• Safety Statements: 26-28-36/37/39-45-61-28A
• RIDADR: UN 2928 6.1/PG 2
• WGK Germany: 2
• RTECS: SZ7100000
• HazardClass: 6.1
• PackingGroup: II
• Hazardous Substances Data: 16672-87-0(Hazardous Substances Data)

Usage

Chemical Properties

Different sources of media describe the Chemical Properties of 16672-87-0 differently. You can refer to the following data:
1. white to beige powder
2. Ethephon is a white to tan powder. Commercial product is a white, waxy solid. Commercial products may be available as aqueous solutions or soluble concentrates.

Uses

Different sources of media describe the Uses of 16672-87-0 differently. You can refer to the following data:
1. 2-Chloroethyl)phosphonic acid (Ethephon) is the most widely used plant growth regulator. Ethephon is often used on wheat, coffee, tobacco, cotton, and rice in order to help the plant's fruit reach mat urity more quickly. The toxicity of Ethephon is actually very low, and any Ethephon used on the plant is converted very quickly to ethylene.
2. Plant growth regulator.
3. Accelerates the preharvest ripening of fruits and vegetables.

Definition

ChEBI: A phosphonic acid compound having a 2-chloroethyl substituent attached to the P-atom.

Agricultural Uses

Plant growth regulator: Ethephon is a plant growth regulator used to promote fruit ripening, abscission, flower induction, and other responses. It is registered for use on a number of food, feed and nonfood crops (rubber plants, flax), greenhouse nursery stock, and outdoor residential ornamental plants, but is used primarily on cotton. Ethephon is applied to plant foliage by either ground or aerial equipment. It also may be applied by hand sprayer to certain home garden vegetables and ornamentals. Use practice limitations include prohibitions against applying ethephon through any type of irrigation system; feeding or grazing livestock in treated areas; and treating within 2 to 60 days of harvest, depending on the crop.

Trade name

AMCHEM? 68-250; ARVEST?; BASE? 250; BOLL’D?; BROMEFLOR?; BROMOFLOR?; CAMPOSAN?; CEPHA?; CEPHA? 10LS; CERONE?; CHIPCO? FLOREL PRO; ETHEPON?; ETHEL?; ETHEVERSE?; ETHREL?; FINISH?; FLORDIMEX?; FLOREL?; G-996?; KAMPOSAN?; PREP?; ROLLFRUCT?; TERPAL? (with mepiquat chloride); T-EXTRA?; TOMATHREL?

Safety Profile

Moderately toxic by ingestion. Mddly toxic by skin contact. A plant growth regulator. Caution: Spray formulations are quite acidic, about pH 1 .O. May be irritating to exposed skin and eyes, or if inhaled. When heated to decomposition it emits toxic fumes of Cl and POx.

Potential Exposure

Ethephon is an organophosphonate plant growth regulator used to promote fruit ripening, abscission, flower induction, and other responses. It is registered for use on a number of food, animal feed and nonfood crops (rubber plants, flax), greenhouse nursery stock, and outdoor residential ornamental plants, but is used primarily on cotton. Ethephon is applied to plant foliage by either ground or aerial equipment. It also may be applied by hand sprayer to certain home garden vegetables and ornamentals. Use practice limitations include prohibitions against applying ethephon through any type of irrigation system; feeding or grazing livestock in treated areas; and treating within 2 to 60 days of harvest, depending on the crop

Environmental Fate

Soil. Degrades rapidly in soil to phosphoric acid, ethylene and chloride ions (Hartley and Kidd, 1987) and naturally occurring substances (Humburg et al., 1989). Chemical/Physical. In an aqueous solution at pH 3.5, ethepon begins to hydrolyze, releasing ethylene (Windholz et al., 1983).

Shipping

UN2928 Toxic solids, corrosive, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, 8-Corrosive material, Technical Name Required

Incompatibilities

Hygroscopic. Aqueous solutions are highly acidic. May cause corrosion if metals, especially when moisture is present. Contact with flammable material may cause fire and explosions. Contact with combustible or oxidizable materials may form heat-, shock-, and frictionsensitive explosive mixtures. Static electricity may also cause explosions. Keep away from all acids, especially dibasic organic acids, ammonium compounds, antimony sulfide, arsenic trioxide, metal sulfides, powdered metals, calcium aluminum hydride, cyanides, manganese dioxide, phosphorus, selenium, sulfur, thiocyanates, and zinc.

Waste Disposal

Destruction by alkali hydrolysis or incineration. Containers must be disposed of properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office.

InChI:InChI=1/C2H6ClO3P/c3-1-2-7(4,5)6/h1-2H2,(H2,4,5,6)/p-2

Synthetic route

dimethyl 2-chloroethylphosphonate (26119-41-5) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride at 110℃; for 9h; atmospheric pressure;	93%
With hydrogenchloride In water for 24h; Heating; Yield given;

di(trimethylsilyl)-2-chloroethylphosphonate (67344-36-9) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With water at 20℃; for 1h;	90%
With water

diisopropyl 2-chloroethylphosphonate (25131-74-2) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride for 24h; Heating;	90%
With hydrogenchloride In water at 130 - 140℃; Microwave irradiation; Sealed tube;	84%
With hydrogenchloride In water for 24h; Heating;	80%

diethyl 2-chloroethylphosphonate (10419-79-1) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride at 110℃; for 12h; atmospheric pressure;	88%
With hydrogenchloride In water at 100℃; for 0.416667h; Microwave irradiation; Sealed tube;	79%

dipropyl 2-chloroethylphosphonate (88093-47-4) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride at 120℃; under 3800 Torr; for 15h;	80%

dibutyl 2-chloroethylphosphonate (20135-59-5) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride at 120℃; under 3800 Torr; for 16h;	75%
With hydrogenchloride In water for 24h; Heating; Yield given;

dipentyl 2-chloroethylphosphonate → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride at 120℃; under 3800 Torr; for 19h;	73%

bis(2-chloroethyl) 2-chloroethylphosphonate (6294-34-4) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride at 100 - 110℃;	10%
With hydrogenchloride at 150 - 160℃;

1,2-dichloro-ethane (107-06-2) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
(i) PCl3, AlCl3, (ii) diethyl phthalate, SO2, (iii) H2O; Multistep reaction;

2-acetoxyethanephosphonic acid dimethyl ester (39118-50-8) → 2-chloroethylphosphonic acid (16672-87-0) + β-Hydroxyethanphosphonsaeure (22987-21-9) + β-Acetoxyethanphosphonsaeure (32541-80-3)

Conditions	Yield
With hydrogenchloride In water at 100℃; for 11h;	A 3 % Spectr. B 77 % Spectr. C 18 % Spectr.
With water at 160℃; for 6.5h; Product distribution; hydrolysis, reagent, temperature;	A 3 % Spectr. B 77 % Spectr. C 18 % Spectr.

2-Acetoxyethanphosphonseauredichlorid (50655-62-4) → vinylphosphonic acid (1746-03-8) + 2-chloroethylphosphonic acid (16672-87-0) + β-Hydroxyethanphosphonsaeure (22987-21-9) + β-Acetoxyethanphosphonsaeure (32541-80-3) + 2-(2-Hydroxyethan-hydrogenphosphonato)-ethanphosphonseaure

Conditions	Yield
With water at 30 - 35℃; for 24h; Product distribution; hydrolysis, temperature;	A 0.4 % Spectr. B 3.4 % Spectr. C 60 % Spectr. D 30 % Spectr. E 4.4 % Spectr.

bis(2-chloroethyl) 2-chloroethylphosphonate (6294-34-4) → 2-chloroethylphosphonic acid (16672-87-0) + 2-chloroethyl monoester of 2-chloroethyl-phosphonic acid

Conditions	Yield
With hydrogenchloride In water for 24h; Heating; Yield given;

hydrogenchloride (7647-01-0) + bis(2-chloroethyl) 2-chloroethylphosphonate (6294-34-4) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
at 150 - 160℃;

bis(2-chloroethyl) 2-chloroethylphosphonate (6294-34-4) → 2-chloroethylphosphonic acid (16672-87-0) + β-Hydroxyethanphosphonsaeure (22987-21-9) + 1,2-dichloro-ethane (107-06-2) + 2-chloro-ethanol (107-07-3)

Conditions	Yield
With hydrogenchloride at 120℃; under 3800 Torr; for 16h; Product distribution; Further Variations:; Pressures; Temperatures;

chloroethane (75-00-3) + chloroethylene (75-01-4) + diethyl 2-chloroethylphosphonate (10419-79-1) + Diethyl phosphonate (762-04-9, 123-22-8) → 2-chloroethylphosphonic acid (16672-87-0)

dibutyl hydrogen phosphite (1809-19-4) + phosphonic Acid (13598-36-2) + chloroethylene (75-01-4) + Phosphoric acid mono-n-butylester (16456-56-7) → 2-chloroethylphosphonic acid (16672-87-0) + dibutyl 2-chloroethylphosphonate (20135-59-5) + 2-chloroethylphosphonic acid monobutyl ether (1118607-72-9)

Conditions	Yield
With di-tert-butyl peroxide at 125 - 130℃; for 14h; Product distribution / selectivity;

dibutyl 2-chloroethylphosphonate (20135-59-5) + 2-chloroethylphosphonic acid monobutyl ether (1118607-72-9) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride; water at 120 - 125℃; for 2h; Product distribution / selectivity;

bis(2-chloroethyl) 2-chloroethylphosphonate (6294-34-4) → 2-chloroethylphosphonic acid (16672-87-0) + 1,2-dichloro-ethane (107-06-2)

Conditions	Yield
With hydrogenchloride at 150℃; under 3750.38 Torr; High pressure;

Tris(2-chloroethyl) phosphate (115-96-8) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With hydrogenchloride at 150℃; for 80h; Large scale;

(2-chloroethyl)phosphonic dichloride (690-12-0) → 2-chloroethylphosphonic acid (16672-87-0)

Conditions	Yield
With water at 80 - 85℃; for 1h; Large scale;	103.5 kg

2-chloroethylphosphonic acid (16672-87-0) → (2-iodoethyl)phosphonic acid (7582-45-8)

Conditions	Yield
With hydrogen iodide for 5h; Heating;	88%
With sodium iodide In acetone

2-chloroethylphosphonic acid (16672-87-0) + ammonia (7664-41-7) → (2-aminethyl)phosphonic acid (2041-14-7)

Conditions	Yield
With sodium hydroxide; potassium iodide at 20℃; for 172h; pH=8; Substitution; Acid hydrolysis;	88%

2-chloroethylphosphonic acid (16672-87-0) + ethylenediamine (107-15-3) → [2-(2-amino-ethylamino)-ethyl]-phosphonic acid (112013-36-2)

Conditions	Yield
With sodium hydroxide; potassium iodide at 20℃; for 172h; pH=8; Substitution; Acid hydrolysis;	86.5%

2-chloroethylphosphonic acid (16672-87-0) + guanidine nitrate (113-00-8) → 2-Guanidinoethylphosphonic acid (55215-15-1)

Conditions	Yield
With sodium hydroxide; potassium iodide at 20℃; for 172h; pH=8; Substitution; Acid hydrolysis;	85.2%

2-chloroethylphosphonic acid (16672-87-0) + benzylamine (100-46-9) → acide N-benzylamino-2 ethylphosphonique (72696-92-5)

Conditions	Yield
With sodium hydroxide; potassium iodide at 20℃; for 172h; pH=8; Substitution; Acid hydrolysis;	84.5%

propylamine (107-10-8) + 2-chloroethylphosphonic acid (16672-87-0) → acide N-propylamino-2 ethylphosphonique (79782-63-1)

Conditions	Yield
With sodium hydroxide; potassium iodide at 20℃; for 172h; pH=8; Substitution; Acid hydrolysis;	79.9%

2-chloroethylphosphonic acid (16672-87-0) + dimethyl amine (124-40-3) → 2-(dimethylamino)ethylphosphonate (14596-56-6)

Conditions	Yield
With sodium hydroxide; potassium iodide at 20℃; for 172h; pH=8; Substitution; Acid hydrolysis;	79.3%

2-chloroethylphosphonic acid (16672-87-0) + diethylamine (109-89-7) → (2-diethylamino-ethyl)-phosphonic acid (69303-27-1)

Conditions	Yield
With sodium hydroxide; potassium iodide at 20℃; for 172h; pH=8; Substitution; Acid hydrolysis;	79.2%

2-chloroethylphosphonic acid (16672-87-0) + methylamine (74-89-5) → 2-(N-methylamino)ethylphosphonic acid (14596-55-5)

Conditions	Yield
With sodium hydroxide; potassium iodide at 20℃; for 172h; pH=8; Substitution; Acid hydrolysis;	78.2%

2-chloroethylphosphonic acid (16672-87-0) + (E)-14-iodotetradeca-13-en-3,5-diyn-1-ol → C16H23ClIO3P

Conditions	Yield
Stage #1: 2-chloroethylphosphonic acid With dicyclohexyl-carbodiimide In dichloromethane for 0.25h; Inert atmosphere; Stage #2: (E)-14-iodotetradeca-13-en-3,5-diyn-1-ol In dichloromethane at 20℃; for 48h; Inert atmosphere;	75%

2-chloroethylphosphonic acid (16672-87-0) + methylamine hydrochloride (593-51-1) → 2-(N-methylamino)ethylphosphonic acid (14596-55-5)

Conditions	Yield
With sodium hydride In N,N-dimethyl-formamide at 20℃; for 0.5h;	72%

cis-Mo(CO)4(PPh2Cl)2 (23581-79-5, 37834-17-6, 42724-61-8) + 2-chloroethylphosphonic acid (16672-87-0) → Mo(CO)4{(P(C6H5)2O)2P(O)CH2CH2Cl} (96679-93-5)

Conditions	Yield
With triethylamine In tetrahydrofuran byproducts: (Et3NH)Cl; recrystn. from dichloromethane/hexanes mixtures;	50.4%

(2-aminoethyl)methylsulfide (18542-42-2) + 2-chloroethylphosphonic acid (16672-87-0) → C5H14NO3PS

Conditions	Yield
With sodium hydride In N,N-dimethyl-formamide at 20℃; for 0.5h;	50%

2-chloroethylphosphonic acid (16672-87-0) + hexan-1-ol (111-27-3) → (2-chloro-ethyl)-phosphonic acid dihexyl ester (6924-92-1)

Conditions	Yield
With triethylamine

oxirane (75-21-8) + 2-chloroethylphosphonic acid (16672-87-0) → Di-O-β-hydroxyaethyl-β-chloraethylphosphonat (59259-24-4)

Conditions	Yield
In benzene

2-chloroethylphosphonic acid (16672-87-0) → ethene (74-85-1) + vinylphosphonic acid (1746-03-8) + β-Hydroxyethanphosphonsaeure (22987-21-9)

Conditions	Yield
With sodium hydroxide Mechanism; Product distribution; other 2-haloethylphosphonic acids or esters; var. aqueous and non-aqueous solvents, var. times, var. temp., var. pH; isotopic effect;

Upstream product

• 67344-36-9 di(trimethylsilyl)-2-chloroethylphosphonate 
• 25131-74-2 diisopropyl 2-chloroethylphosphonate 
• 10419-79-1 diethyl 2-chloroethylphosphonate 
• 88093-47-4 dipropyl 2-chloroethylphosphonate 
• 6294-34-4 bis(2-chloroethyl) 2-chloroethylphosphonate 
• 75-00-3 chloroethane 
• 75-01-4 chloroethylene 
• 762-04-9 Diethyl phosphonate 
• 690-12-0 (2-chloroethyl)phosphonic dichloride 
• 115-96-8 Tris(2-chloroethyl) phosphate 
• 20135-59-5 dibutyl 2-chloroethylphosphonate 
• 1118607-72-9 2-chloroethylphosphonic acid monobutyl ether 
• 1809-19-4 dibutyl hydrogen phosphite 
• 13598-36-2 phosphonic Acid 

Downstream Products

• 2041-14-7 (2-aminethyl)phosphonic acid 
• 14596-56-6 2-(dimethylamino)ethylphosphonate 
• 14596-55-5 2-(N-methylamino)ethylphosphonic acid 
• 22987-21-9 β-Hydroxyethanphosphonsaeure 
• 1746-03-8 vinylphosphonic acid 
• 96679-93-5 Mo(CO)4{(P(C₆H₅)2O)2P(O)CH₂CH₂Cl} 
• 74-85-1 ethene 
• 72696-92-5 acide N-benzylamino-2 ethylphosphonique 
• 55215-15-1 2-Guanidinoethanphosphorsaeure 

Related news

Effects of Ethephon (cas 16672-87-0) and Abscisic Acid Application on Ripening-Related Genes in ‘Kohi’ Kiwifruit (Actinidia chinensis) on the Vine10/01/2019

The effects of ethephon and abscisic acid (ABA) application on ripening-related genes of pre-harvest ‘Kohi’ kiwifruit (Actinidia chinensis) were studied to clarify the possibility of the fruit ripening on the vine. The fruits were treated on the vine at mature stage with 250 µL⋅L−1 ethephon o...detailed

Effects of pre-harvest application of Ethephon (cas 16672-87-0) or abscisic acid on ‘Kohi’ kiwifruit (Actinidia chinensis) ripening on the vine09/27/2019

The effects of ethephon, abscisic acid (ABA), and nordihydroguaiaretic acid (NDGA) application on the ripening of pre-harvest ‘Kohi’ kiwifruit (Actinidia chinensis) were studied. The fruits were treated on-vine at 155 days after full bloom (DAFB) (mature stage) with 250 μL/L ethephon, 100 μm...detailed

Effects of Ethephon (cas 16672-87-0) and methyl jasmonate on physicochemical properties of Acacia seyal var. seyal (L.) gum produced in Sudan09/26/2019

The study aimed to investigate the effect of two plant growth regulators, namely ethephon (Eth) and methyl jasmonate (Ja-Me) at different concentrations and combinations (1% Eth; 1% Ja-Me; 5% Ja-Me; 1% Eth+1% Ja-Me; and 1% Eth+5% Ja-Me) on physicochemical properties of Acacia seyal var. seyal gu...detailed

Research paperGenome-wide identification of differentially expressed miRNAs induced by Ethephon (cas 16672-87-0) treatment in abscission layer cells of cotton (Gossypium hirsutum)09/25/2019

Cotton is one of the most important economic crops and its production is influenced by various adverse factors. Boll shedding at an inappropriate period causes the severe loss of cotton yield. Ethephon can promote the formation of abscission layer cells, resulting in boll shedding. To genome-wid...detailed

RESEARCH ARTICLEDissipation and residue of Ethephon (cas 16672-87-0) in maize field09/09/2019

A rapid and reliable method was developed for analysis of ethephon residues in maize, in combination with the investigation of its dissipation in field condition and stabilities during the sample storage. The residue analytical method in maize plant, maize kernel and soil was developed based on ...detailed

The effect of Ethephon (cas 16672-87-0) on immune system in male offspring of mice09/08/2019

Ethephon can liberate ethylene which could interfere the plant growth process. The aim of the present study was to determine the effect of ethephon on developing immune system of male offspring. Ethephon could enhance NK cell activity in male mice. For 4-week-old male mice, lymphocytes of periph...detailed

Postharvest Ethephon (cas 16672-87-0) degreening improves fruit color, flavor quality and increases antioxidant capacity in ‘Eureka’ lemon (Citrus limon (L.) Burm. f.)09/07/2019

External color of citrus fruits is a key factor that affects consumer acceptability, and ethephon has been commonly used to the degreening of citrus fruits in the industry. In this study, the green-peeled ‘Eureka’ lemon fruits were treated with ethephon solution (1000 mg/L), and then stored at...detailed

Relevant articles and documents

An efficient protocol for the synthesis of 2-chloroethylphosphonic acid

An efficient synthetic route to prepare 2-chloroethyl-phosphonic acid (ethephon) with high purity was developed.

Joint production method of ethephon and vinylphosphonic acid

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.

Ethephon by-product 2-chloro ethyl-anhydride conversion into 2-chloro ethyl phosphonic acid method (by machine translation)

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.

Preparation of high quality ethephon using domestic diester bis-(2-chloroethyl)-2-chloroethylphosphonate as substrate

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.

Microwave-assisted hydrolysis of phosphonate diesters: An efficient protocol for the preparation of phosphonic acids

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).

Process for making a plant growth regulator

A method for making a plant growth regulator includes the step of reacting vinyl chloride with a phosphorous reagent.

Comparative study on hydrolysis of 2-chloroethylphosphonic acid dialkylesters

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.

Patch preparations for treating plants

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.

Optimization of 2-chloroethylphosphonic acid synthesis by acid hydrolysis of dialkyl-2-chloroethylphosphonate compounds. Influence of the nature of alkyl phosphonate functions

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

Process for the production of aliphatic phosphonic acids

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.