94-75-7

Hazards Identification

Pictogram(s):

Signal:

Danger

GHS Hazard Statements:

H302: Harmful if swallowed [Warning Acute toxicity, oral]
H317: May cause an allergic skin reaction [Warning Sensitization, Skin]
H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]
H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]
H412: Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard]

Precautionary Statement Codes:

P261, P264, P264+P265, P270, P271, P272, P273, P280, P301+P317, P302+P352, P304+P340, P305+P354+P338, P317, P319, P321, P330, P333+P313, P362+P364, P403+P233, P405, and P501

Hazard Classes and Categories:

Acute Tox. 4 *
STOT SE 3
Eye Dam. 1
Skin Sens. 1
Aquatic Chronic 3
Acute Tox. 4 (100%)
Skin Sens. 1 (93.33%)
Eye Dam. 1 (93.33%)
Aquatic Chronic 2 (93.33%)
Acute toxicity - category 4
Specific target organ toxicity (single exposure) - category 3
Eye damage - category 1
Skin sensitisation - category 1
Hazardous to the aquatic environment (chronic) - category 3
Acute toxicity (Oral) - Category 4
Serious eye damage/eye irritation - Category 2A
Carcinogenicity - Category 2
Reproductive toxicity - Category 2
Specific target organ toxicity - Single exposure - Category 1 (nervous system)_x000D_ Category 3 (narcotic effects)
Specific target organ toxicity - Repeated exposure - Category 1 (nervous system, haemal system, liver, kidney)
Hazardous to the aquatic environment (Acute) - Category 3
Hazardous to the aquatic environment (Long-term) - Category 3
Acute toxicity (Dermal) - Category 5
Acute toxicity (Inhalation: Dusts and mists) - Category 4
Skin corrosion/irritation - Category 3
Serious eye damage/eye irritation - Category 2B
Specific target organ toxicity - Repeated exposure - Category 2 (liver)
Hazardous to the aquatic environment (Acute) - Category 1
Hazardous to the aquatic environment (Long-term) - Category 1
Carcinogens

Hazards Summary:

2,4-Dichlorophenoxyacetic acid (2,4-D) does not occur naturally in the environment. 2,4-D is the active ingredient in many products used in the United States and throughout the world as an herbicide to kill weeds on land and in the water. There are nine forms of 2,4-D that can be used as an herbicide and it is typically sold as a powder or in a liquid form.

Usage

References

https://www.nrdc.org/stories/24-d-most-dangerous-pesticide-youve-never-heard https://pubchem.ncbi.nlm.nih.gov/compound/1486#section=Top https://en.wikipedia.org/wiki/2,4-Dichlorophenoxyacetic_acid

Chemical Properties

2,4-Dichlorophenoxyacetic acid is a white to yellow crystalline powder with a slight phenolic odor. It is used as a herbicide for the selective control of broad-leaved weeds in agriculture, and for the control of woody plants along roadsides, railways, and utilities rights of way. It is one of the most widely used herbicides in the world and is commonly used on crops such as wheat and corn, and on pasture and rangelands. It is also used to control broad-leaved aquatic weeds.

Physical properties

Odorless, white to pale yellow, powder or prismatic crystals. Impure formulations containing 2,4- D as the main component may have a phenolic odor.

Uses

Different sources of media describe the Uses of 94-75-7 differently. You can refer to the following data:
1. 2,4-D is registered with the US Environmental Protection Agency (EPA) for use on a variety of food/feed sites, turf, lawn, aquatic sites, and forestry applications, and as a growth regulator in citrus crops. Residents and professional applicators may use 2,4-D on home lawns.
2. 2,4-Dichlorophenoxyacetic acid is often formulated as various forms of inorganic salts or esters. 2,4-D was first registered as a herbicide in 1948, and its annual production was estimated at 52–67 million lb in 1990. The primary use of 2,4-D is for control of broadleaf weeds, and as such, it is used for a large spectrum of applications in agriculture, forestry, and lawn care. 2,4-D also is used along right-ofways, on rangelands, parks, and in aquatic environments.
3. 2,4-D is one of the most widely used herbicides. It is a chlorine-substituted phenoxyacetic acid herbicide used for postemergence control of annual and perennial broad-leaved weeds in fruits, vegetables, turfs and ornamentals.Exposure to this chemical may arisein the garden, farm, or plantation setting,where it is sprayed for weed control andto enhance the plant growth. Its residueshave been detected in soils, sediments, andgroundwater, as well as in tissues of corals(Crockett et al. 1986; Glynn et al. 1984).

Preparation

Two processes are currently used for the production of 2,4-Dichlorophenoxyacetic acid. In the first process, phenol is condensed with chloroacetic acid forming phenoxyacetic acid, which is subsequently chlorinated. In the second process, phenol is chlorinated, generating 2,4-dichlorophenol, which is subsequently condensed with chloroacetic acid. The butyl ester derivative of 2,4-D is produced by the esterification of the acid with butanol in the presence of a ferric chloride catalyst and chlorine (Liu et al., 2013). Preparation of 2,4-Dichlorophenoxyacetic acid

Definition

ChEBI: A chlorophenoxyacetic acid that is phenoxyacetic acid in which the ring hydrogens at postions 2 and 4 are substituted by chlorines.

General Description

Odorless white to tan solid. Sinks in water.

Air & Water Reactions

Decomposes rapidly in water.

Reactivity Profile

2,4-Dichlorophenoxyacetic acid is incompatible with strong oxidizers. 2,4-Dichlorophenoxyacetic acid is corrosive to metals.

Health Hazard

The acute toxic symptoms from ingestion,absorption through skin, and inhalation ofits dusts include lethargy, stupor, weakness,incoordination, muscular twitch, nausea, vomiting, gastritis, convulsions, and coma.Death resulted in animals from ventricularfibrillation. In humans, ingestion of 4–6 gof 2,4-D can cause death. The toxic effectsare nausea, vomiting, somnolence, convul-sions, and coma. The oral LD50 value in testanimals varied at 100–500 mg/kg, depend-ing on species, which included dogs, guineapigs, hamsters, rats, mice, and rabbits. Gorzinski and co-workers (1987) have investigated acute, pharmacokinetic, and subchronic toxicity of 2,4-D and its estersand salts in rats and rabbits. The acutedermal LD50 values in rabbits for theacid, esters, and salts were >2000 mg/kg.Urinary elimination of 2,4-D was saturatedin male rats given oral doses of 50 mg/kg.There was a decrease in body weightgain and increase in kidney weightsin animals, resulting from subchronicdietary doses. A dose-related degenerativechange was observed in the proximalrenal tubules. Repeated subcutaneous dosing(150–250 mg/kg) of 2,4-D butyl esterresulted in accumulation of the compoundin the brain, causing neurobehavioral toxicity(Schulze and Dougherty 1988). Alexander and associates (1985) determined the 48-hour median lethal con-centration values for 2,4-D to aquatic organ-isms. These values are 25, 325, 290, and358 mg/L for Daphnia magna, fathead min-nows, bluegill, and rainbow trout, respec-tively.

Fire Hazard

Special Hazards of Combustion Products: Toxic and irritating hydrogen chloride or phosgene gases may form.

Agricultural Uses

Herbicide, Plant growth regulator: 2,4-Dichlorophenoxyacetic acid was introduced as a plant growth-regulator in 1942. 2, 4-D is the most widely used herbicide in the United States and its used in more than 100 countries. It is registered in the United States as a herbicide for control of broadleaf plants and as a plant growth-regulator. There are many forms or derivatives of 2,4-D including esters, amines, and salts. It is used in cultivated agriculture, in pasture and rangeland applications, forest management, home, garden, and to control aquatic vegetation. It may be found in emulsion form, in aqueous solutions (salts), and as a dry compound. The product Agent Orange, made by Monsanto Chemical and used extensively throughout Vietnam, was about 50% 2,4-D. However, the controversies associated with the use of Agent Orange involved a contaminant (dioxin) in the 2,4,5-T component of the defoliant. In 1964 Agent Orange replaced Agent Purple a mixture of the n-butyl esters of 2,4-D and 2,4,5-T plus the isobutyl ester of 2,4,5-T.

Trade name

Hedonal; 2,4-D; Estone; Agrotect; Fernesta; Fernimine; Netagrone; Tributon; Vergemaster; Amoxone; Dicopur; Dormone; Ipaner; Moxone; Phenox; Pielik; Rhodia; Weedone; B-Selektonon.

Potential Exposure

2,4-Dichlorophenoxyacetic acid, was introduced as a plant growth-regulator in 1942. It is registered in the United States as a herbicide for control of broadleaf plants and as a plant growth-regulator. Thus, workers engaged in manufacture, formulation or application are affected, as may be citizens in areas of application. The Vietnam war era defoliant, Agent Orange, was a mixture of 2,4-D and 2,4,5-T.

Carcinogenicity

Collectively, the epidemiological and toxicological data show that 2,4-D is not likely to be carcinogenic in humans unless it is acting through an unknown mechanism that is not evident in animals. According to the calculated RfD and data from exposure studies, the general public should not experience toxic effects from exposure to 2,4-D. Because workers involved in the manufacture or application of 2,4-D may be exposed to levels above the RfD, appropriate protective equipment should be used.

Environmental Fate

2,4-Dichlorophenoxyacetic acid (2,4-d) is rapidly degraded by microbes in soil and water, with a half-life of 3-22 days in different soils. 2,4-d is weakly sorbed by soil with sorption generally increasing with increasing soil organic carbon content. Leaching to groundwater is most likely in coarse-grained sandy soils with low organic content or with very basic soils. In general, little runoff occurs with 2,4-d or its amine salts.

Metabolism

Chemical. 2,4-D and its salts are very stable, but esters are sensitive to hydrolysis under acidic and basic conditions. In the field, 2,4-D losses due to photodegradation are minor. 2,4-D is a strong acid and forms water-soluble salts with amines and alkali metals. A sequestering agent is included in 2,4-D formulations to prevent precipitation of Ca2+ andMg2+ salts in hard water. Plant. 2,4-D detoxification occurs relatively slowly in plants. There are many possible routes of detoxification, and these are usually grouped into those reactions that are consistent with phase I metabolism and those that are consistent with phase II metabolism. Phase I reactions that have been observed to occur with 2,4-D include dechlorination, decarboxylation, hydroxylation, and dealkylation. Phase II reactions that have been observed to occur with 2,4-D include conjugation of the side chain to amino acids, particularly glutamate and aspartate, and glucose conjugation following hydroxylation of the phenoxy ring. Selectivity differences among broadleaf species may be accounted for by differences in the rates of 2,4-D detoxification. Soil. Microbial degradation in the soil involves cleavage of the acid side chain, decarboxylation, hydroxylation, and ring opening.

Shipping

UN3345 Phenoxyacetic acid derivative pesticide, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. A DOT regulated marine pollutant.

Purification Methods

Crystallise 2,4-D from MeOH. It is a plant growth substance, a herbicide and is TOXIC. [Beilstein 6 IV 908.]

Toxicity evaluation

2,4-D is excreted unchanged in the urine of humans and rat. When used under normal conditions, 2,4-D does not appear to produce acute toxic effects on any animal species. The acute oral LD50s of 2,4- D in rat and mouse are 639–764 mg/kg, and 138 mg/kg, respectively.

Incompatibilities

A weak acid, incompatible with bases. Decomposes in sunlight or heat, forming hydrogen chloride and phosgene. Contact with strong oxidizers may cause fire and explosions.

Waste Disposal

Incineration of phenoxys is effective in 1 second @ 982 C, using a straight combustion process or @ 482℃ using catalytic combustion. Over 99% decomposition was reported when small amounts of 2,4-D were burned in a polyethylene bag. See "References" for additional detail. In accordance with 40CFR165, follow (31); recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by follow- ing (100) Package (2) label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office. Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal.

InChI:InChI=1/C8H6Cl2O3/c9-8(10,7(11)12)13-6-4-2-1-3-5-6/h1-5H,(H,11,12)

Synthetic route

methyl 2,4-dichlorophenoxyacetate (1928-38-7) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With hydrogenchloride; para-dodecylbenzenesulfonic acid In water at 160℃; for 1h; Temperature; Reagent/catalyst;	99.6%
With toluene-4-sulfonic acid In water at 106℃; for 3h;	99.9%
With hydrogenchloride; water for 3h; Reflux;	98.3%

2-phenoxyacetic acid (122-59-8) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With (phthalocyaninato)iron(II); chlorine; acetic acid In water at 75℃; for 0.5h; Concentration; Time;	99.8%
With dihydrogen peroxide; chlorine In benzene at 100℃; for 1h;	99%
With iron(III) chloride; dimethylsulfide; chlorine In chloroform at 70℃; for 5h; Reagent/catalyst; Solvent; Temperature;	99.4%

bromoacetic acid (79-08-3) + 2,4-dichlorophenol (120-83-2) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
Stage #1: bromoacetic acid With water; potassium hydroxide at 110℃; for 2h; Green chemistry; Stage #2: 2,4-dichlorophenol With water; sodium hydroxide at 100 - 130℃; for 4.5h; Green chemistry; Stage #3: With sulfuric acid at 140℃; under 3000.3 Torr; for 2h; Green chemistry;	99.8%

(2-chlorophenoxy)acetic acid (614-61-9) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With N-chloro-N-(benzenesulfonyl)benzenesulfonamide In acetonitrile at 20 - 25℃; for 0.0833333h; Green chemistry;	99.7%
With hydrogenchloride; sodium chlorate; acetic acid

chloroacetic acid (79-11-8) + 2,4-dichlorophenol (120-83-2) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
Stage #1: chloroacetic acid With sodium hydroxide In water for 1h; Stage #2: 2,4-dichlorophenol With potassium hydroxide In water for 1h; Stage #3: With tetrabutylammomium bromide; potassium bromide In water at 130℃; for 2h; Reagent/catalyst; Temperature;	99.6%
Stage #1: chloroacetic acid With water; sodium carbonate at 100℃; for 1h; Green chemistry; Stage #2: 2,4-dichlorophenol With water; potassium hydroxide at 90 - 100℃; for 6h; Green chemistry; Stage #3: With hydrogenchloride In water at 150℃; under 4500.45 Torr; for 2h; Reagent/catalyst; Temperature; Green chemistry;	99.7%
With sodium hydroxide Irradiation;	95%

ethyl 2,4-dichlorophenoxyacetate (533-23-3) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With sodium hydroxide at 100℃; for 2h;	99.5%
With water; sodium hydroxide for 0.5h; Reflux;	99.5%
With water; sodium hydroxide for 0.5h; Reflux;	99.6%

methyl 2,4-dichlorophenoxyacetate (1928-38-7) → 2,4-Dichlorophenoxyacetic acid (94-75-7) + methylene chloride (74-87-3)

Conditions	Yield
With hydrogenchloride; zinc(II) chloride In water at 140℃; for 4h; Reagent/catalyst; Temperature;	A 99.6% B 98.1%

2,4-dichlorophenoxyacetic acid isooctyl ester (3035-67-4) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With sulfuric acid for 3h; Reagent/catalyst; Reflux;	99.5%
With sulfuric acid for 3h; Reflux;	99.3%
With hydrogenchloride In water for 6h; Reagent/catalyst; Reflux;	222 g

Amchem Weed Killer 650 (94-11-1) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With water; sodium hydroxide Reflux;	99.5%
With sulfuric acid at 90℃; for 2h; Large scale;	2202.1 g
With hydrogenchloride In water at 60℃; for 4h; Large scale;	2200.7 g
With hydrogenchloride; water at 60℃; for 4h; Large scale;	2196.3 g
With hydrogenchloride In water at 60℃; for 4h;	219.49 g

Fernesta (94-80-4) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With water; sodium hydroxide for 0.5h; Reflux;	99.3%
With toluene-4-sulfonic acid In water; butan-1-ol at 120℃; for 2h;	99.3%
Stage #1: Fernesta With sodium hydroxide at 100℃; for 23h; Stage #2: With sulfuric acid	2200 kg

propyl 2,4-dichlorophenoxyacetate (1928-61-6) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With sulfuric acid for 3h; Reflux;	99.3%
With sulfuric acid for 3h; Reflux;	221 g

potassium salt of 2,4-dichlorophenol (50884-30-5) + bromoacetic acid (79-08-3) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
Stage #1: bromoacetic acid With D-sorbitol; sulfuric acid In toluene for 8h; Stage #2: potassium salt of 2,4-dichlorophenol for 4h; Stage #3: With tetrabutyl phosphonium bromide; acetic acid In water for 6h; Reflux;	99.3%

chloroacetic acid (79-11-8) + phenol (108-95-2) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
Stage #1: chloroacetic acid With sodium ethanolate In ethanol Stage #2: phenol With sodium carbonate In ethanol; water at 110℃; Stage #3: With aluminum (III) chloride; sulfuryl dichloride In ethanol; water at 30 - 100℃; for 10h; Reagent/catalyst; Solvent; Temperature;	99.2%

sodium 2,4-dichlorophenoxyacetate (2702-72-9) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With hydrogenchloride In water	98.3%
With hydrogenchloride In water at 0 - 150℃; pH=1 - 2; Reagent/catalyst; Temperature; Large scale;	221 kg

2-Phenoxyethanol (122-99-6) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
Stage #1: 2-Phenoxyethanol With dihydrogen peroxide; sodium hydroxide; manganese(ll) chloride In water at 160℃; for 12h; Stage #2: With chlorine; dimethylphenylsulfide; magnesium chloride pH=Ca. 10; Temperature; Reagent/catalyst;	96.2%
Stage #1: 2-Phenoxyethanol With silica gel; ozone In water at 120℃; for 12h; Stage #2: With sulfuryl dichloride; formamide In water at 80℃; Reagent/catalyst;	217.4 g
Multi-step reaction with 2 steps 1: aluminum oxide; chlorine / 0.5 h / -20 °C 2: oxygen / water / 90 - 130 °C / 5250.53 Torr View Scheme

sodium monochloroacetic acid (3926-62-3) + sodium 2,4-dichlorophenolate (3757-76-4) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
at 130℃; for 5h;	90%
Stage #1: sodium monochloroacetic acid; sodium 2,4-dichlorophenolate at 130℃; for 5h; Stage #2: With hydrogenchloride In water at 10℃; for 1h;	204 g
Stage #1: sodium monochloroacetic acid; sodium 2,4-dichlorophenolate at 150℃; for 5h; Stage #2: With hydrogenchloride In water at 10℃; for 1h; Temperature; Reagent/catalyst; Solvent;	221 g

sodium monochloroacetic acid (3926-62-3) + 2,4-dichlorophenol (120-83-2) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With sodium hydroxide In ethanol; water for 1h; Reflux;	81.6%

benzene (57357-22-9) → 2,4-Dichlorophenoxyacetic acid (94-75-7) + iodobenzene (591-50-4) + 2,4-dichlorophenyl 2,4-dichlorophenoxyacetate (5253-45-2) + 2,4-dichlorophenoxymethyl 2,4-dichlorophenoxyacetate (83143-98-0)

Conditions	Yield
at 200℃; for 0.05h; Heating;	A 15% B 71% C 15% D 64%

4-Chlorophenoxyacetic acid (122-88-3) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With hydrogenchloride; sodium chlorate; acetic acid

2-(2,4-dichlorophenoxy)acetonitrile (3956-63-6) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With sodium hydroxide

2,4-dichlorophenoxyacetic acid amine (1982-42-9) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With sodium hydroxide

sodium 2,4-dichlorophenolate (3757-76-4) + ethyl bromoacetate (105-36-2) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With ethanol Erwaermen des Reaktionsgemisches mit wss. NaOH;

DL-1-(2,4-Dichlor-phenoxy)-3-<2-(3,4-dimethoxyphenyl)-ethylamino>propan-2-ol (104970-08-3) → 2,4-Dichlorophenoxyacetic acid (94-75-7) + 1-Amino-3-(2,4-dichloro-phenoxy)-propan-2-ol (23106-02-7) + 3-(2,4-dichloro-phenoxy)-propane-1,2-diol (34646-53-2) + 2-(3,4-dimethoxyphenyl)-ethylamine (120-20-7) + 4-{2-[3-(2,4-Dichloro-phenoxy)-2-hydroxy-propylamino]-ethyl}-2-methoxy-phenol (121185-84-0) + 2,4-dichlorophenol (120-83-2)

Conditions	Yield
biotransformation;

sodium 2,4-dichlorophenolate (3757-76-4) + chloroacetic acid (79-11-8) → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
In ethyl acetate

Polymer; Monomer(s): N-(2,4-dichlorophenoxyacetyl)diethanolamine; phenylphosphonic dichloride → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With aq. buffer at 25℃; pH=7; Kinetics; Further Variations:; pH-values; Temperatures; Hydrolysis;

iodine (7553-56-2) + acetic acid (64-19-7) + 2-phenoxyacetic acid (122-59-8) + 2 mol chlorine → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
at 20 - 60℃;

acetic acid (64-19-7) + 2-phenoxyacetic acid (122-59-8) + iron + 2 mol chlorine → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
at 20 - 60℃;

sodium-salt of/the/ <2-chloro-phenoxy>-acetic acid → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With sodium hypochlorite; water

sodium-salt of/the/ phenoxyacetic acid → 2,4-Dichlorophenoxyacetic acid (94-75-7)

Conditions	Yield
With sodium hypochlorite; water

2,4-Dichlorophenoxyacetic acid (94-75-7) → 2-(2,4-dichlorophenoxy)acetyl chloride (774-74-3)

Conditions	Yield
With thionyl chloride at 100℃; for 5h; Substitution;	100%
With thionyl chloride; N-benzyl-N,N,N-triethylammonium chloride In chloroform for 4h; Chlorination; Heating;	85%
With thionyl chloride at 75℃; for 2h;	80%

2,4-Dichlorophenoxyacetic acid (94-75-7) + 3-Aminobenzamide (3544-24-9) → 3-(2-(2,4-dichlorophenoxy)acetamido)benzamide

Conditions	Yield
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 20℃;	100%
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 20℃; for 12h; Inert atmosphere;	86.4%

2,4-Dichlorophenoxyacetic acid (94-75-7) + dimethyl amine (124-40-3) → 2,4-dichlorophenoxyacetic acid dimethylamine (2008-39-1)

Conditions	Yield
Stage #1: 2,4-Dichlorophenoxyacetic acid With ethylenediaminetetraacetic acid In tert-butyl methyl ether Stage #2: dimethyl amine In tert-butyl methyl ether at 56℃; pH=8; Product distribution / selectivity;	100%
In water at 20℃; pH=7.1;
In water at 20℃;

2,4-Dichlorophenoxyacetic acid (94-75-7) + 2-nitrophenylmethyl bromide (3958-60-9) → 2,4-D 2-nitrobenzyl ester (1430102-89-8)

Conditions	Yield
With triethylamine In tetrahydrofuran at 73℃;	100%

methanol (67-56-1) + 2,4-Dichlorophenoxyacetic acid (94-75-7) + 2,4-dichlorophenoxyacetic acid dimethylamine (2008-39-1) + (BF3)-MeOH complex → methyl 2,4-dichlorophenoxyacetate (1928-38-7)

Conditions	Yield
Stage #1: 2,4-dichlorophenoxyacetic acid dimethylamine In sodium hydroxide at 80℃; for 0.333333h; pH=14; Hydrolysis; Stage #2: methanol; 2,4-Dichlorophenoxyacetic acid; (BF3)-MeOH complex In diethyl ether pH=2; Esterification; Heating;	99.2%

methanol (67-56-1) + 2,4-Dichlorophenoxyacetic acid (94-75-7) → methyl 2,4-dichlorophenoxyacetate (1928-38-7)

Conditions	Yield
With aminosulfonic acid for 12h; Reflux;	99%
With tert.-butylnitrite at 40℃; for 48h; Green chemistry;	90%
With sulfuric acid at 70℃;	86%
With toluene-4-sulfonic acid Abdestillieren des entstehenden Wassers;

Methyl 3-aminobenzoate (4518-10-9) + 2,4-Dichlorophenoxyacetic acid (94-75-7) → 3-[2-(2,4-dichlorophenoxy)acetylamino]benzoic acid methyl ester

Conditions	Yield
With benzotriazol-1-yloxyl-tris-(pyrrolidino)-phosphonium hexafluorophosphate; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide	99%
With benzotriazol-1-yloxyl-tris-(pyrrolidino)-phosphonium hexafluorophosphate; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide	99%
With benzotriazol-1-ol; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 20℃; for 12h; Inert atmosphere;	30.6%

2,4-Dichlorophenoxyacetic acid (94-75-7) + m-Hydroxyaniline (591-27-5) → 2-(2,4-dichloro-phenoxy)-N-(3-hydroxy-phenyl)-acetamide

Conditions	Yield
With benzotriazol-1-yloxyl-tris-(pyrrolidino)-phosphonium hexafluorophosphate; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 20℃;	99%
With benzotriazol-1-yloxyl-tris-(pyrrolidino)-phosphonium hexafluorophosphate; N-ethyl-N,N-diisopropylamine In N,N-dimethyl-formamide at 20℃;	99%

2,4-Dichlorophenoxyacetic acid (94-75-7) + 1-n-hexadecylpyridinium halide → 1-n-hexadecylpyridinium (2,4-dichlorophenoxy)acetate

Conditions	Yield
Stage #1: 2,4-Dichlorophenoxyacetic acid With sodium hydroxide In water at 50℃; Stage #2: 1-n-hexadecylpyridinium halide In water at 20℃; for 0.5h;	99%

2,4-Dichlorophenoxyacetic acid (94-75-7) + n-hexadecyltrimethylammonium halide → n-hexadecyltrimethylammonium (2,4-dichlorophenoxy)acetate

Conditions	Yield
Stage #1: 2,4-Dichlorophenoxyacetic acid With sodium hydroxide In water at 50℃; Stage #2: n-hexadecyltrimethylammonium halide In water at 20℃; for 0.5h;	99%

2,4-Dichlorophenoxyacetic acid (94-75-7) + 1-n-butyl-1-methylpyrrolidinium halide → 1-n-butyl-1-methylpyrrolidinium (2,4-dichlorophenoxy)acetate (1379462-10-8)

Conditions	Yield
Stage #1: 1-n-butyl-1-methylpyrrolidinium halide With Dowex-Monosphere 550A (OH) anion exchange resin Stage #2: 2,4-Dichlorophenoxyacetic acid for 0.166667h;	99%

2,4-Dichlorophenoxyacetic acid (94-75-7) + Benzophenone oxime (574-66-3) → diphenylmethanone O-(2-(2,4-dichlorophenoxy)acetyl) oxime

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 20℃; Schlenk technique; Inert atmosphere;	99%

2,4-Dichlorophenoxyacetic acid (94-75-7) + lead(II) nitrate + water (7732-18-5) → lead(II) 2,4-dichlorophenoxyacetate monohydrate

Conditions	Yield
With NaOH In water 2,4-dichlorophenoxyacetic acid dissolved in H2O with addition of solid NaOH with heating to about 60°C (equimolar amt. of NaOH and acid);pH was brought to 7 (NaOH); filtered; aq. soln. of Pb(NO3)2 added with vigorously stirring (metal:acid=1:2); ppt. filtered off after 24 h; dried (air) at room temp.; crushed in mortar; elem. anal.;	98.5%

1-hydroxy-pyrrolidine-2,5-dione (6066-82-6) + 2,4-Dichlorophenoxyacetic acid (94-75-7) → (2,4-Dichloro-phenoxy)-acetic acid 2,5-dioxo-pyrrolidin-1-yl ester (93799-60-1)

Conditions	Yield
With dicyclohexyl-carbodiimide In ethyl acetate	98%
With dicyclohexyl-carbodiimide
With dicyclohexyl-carbodiimide In 1,4-dioxane for 0.5h;

2,4-Dichlorophenoxyacetic acid (94-75-7) + 1-n-propoxymethyl-1-methylpiperidinium halide → 1-n-propoxymethyl-1-methylpiperidinium (2,4-dichlorophenoxy)acetate (1379462-07-3)

Conditions	Yield
Stage #1: 1-n-propoxymethyl-1-methylpiperidinium halide With Dowex-Monosphere 550A (OH) anion exchange resin Stage #2: 2,4-Dichlorophenoxyacetic acid for 0.166667h;	98%

2,4-Dichlorophenoxyacetic acid (94-75-7) + 4-n-butyl-4-methylmorpholinium halide → 4-n-butyl-4-methylmorpholinium (2,4-dichlorophenoxy)acetate (1379462-09-5)

Conditions	Yield
Stage #1: 4-n-butyl-4-methylmorpholinium halide With Dowex-Monosphere 550A (OH) anion exchange resin Stage #2: 2,4-Dichlorophenoxyacetic acid for 0.166667h;	98%

Upstream product

• 614-61-9 (2-chlorophenoxy)acetic acid 
• 1982-42-9 2,4-dichlorophenoxyacetic acid amine 
• 79-11-8 chloroacetic acid 
• 120-83-2 2,4-dichlorophenol 
• 122-59-8 2-phenoxyacetic acid 
• 57357-22-9 benzene 
• 7553-56-2 iodine 
• 64-19-7 acetic acid 
• 59-67-6 nicotinic acid 
• 87-89-8 D-myo-inositol 
• 58-56-0 pyridoxal hydrochloride 
• 67-03-8 Thiamine hydrochloride 
• 105-36-2 ethyl bromoacetate 
• 2702-72-9 sodium 2,4-dichlorophenoxyacetate 

Downstream Products

• 15146-99-3 (2,4-dichloro-phenoxy)-acetic acid tetrahydrofurfuryl ester 
• 1928-38-7 methyl 2,4-dichlorophenoxyacetate 
• 74944-83-5 (2,4-dichloro-phenoxy)-acetic acid-(2-ethoxy-ethyl ester) 
• 103425-43-0 (2,4-dichloro-phenoxy)-acetic acid-(2-methoxy-ethyl ester) 
• 1929-73-3 Aqua-Kleen 
• 3625-95-4 (2,4-dichloro-phenoxy)-acetic acid-(3-chloro-but-2-enyl ester) 
• 53404-36-7 (2,4-dichloro-phenoxy)-acetic acid-[2-(2-ethoxy-ethoxy)-ethyl ester] 
• 108759-08-6 1-[(2,4-dichloro-phenoxy)-acetoxy]-2-(2,2-dichloro-propionyloxy)-ethane 
• 120037-00-5 (2,4-dichloro-phenoxy)-acetic acid cholesteryl ester 
• 6294-00-4 2-(2,4-dichlorophenoxy)ethyl (2,4-dichlorophenoxy)acetate 
• 80913-72-0 N-[(2,4-dichloro-phenoxy)-acetyl]-DL-aspartic acid 
• 575-89-3 2-(2,4,6-trichlorophenoxy)acetic acid 
• 120-67-2 2-(2,4-dichlorophenoxy)ethanol 
• 1982-42-9 2,4-dichlorophenoxyacetic acid amine 

Relevant academic research and scientific papers

Design, docking, synthesis, and characterization of novel N'(2-phenoxyacetyl) nicotinohydrazide and N'(2-phenoxyacetyl)isonicotinohydrazide derivatives as anti-inflammatory and analgesic agents

Inflammation is the complex biological response of vascular tissues, which is partly determined by prostaglandins (PLA2). The cyclooxygenase (COX) enzyme exists in two isoforms: COX-1 and COX-2 and by the action of this, the PGs are produced. Besides, nonsteroidal anti-inflammatory drugs (NSAIDs) are therapeutic agents useful in the treatment of inflammation. Encouraged by this, the new derivatives of N'(2-phenoxyacetyl)nicotinohydrazide 9(a-e) and N'(2-phenoxyacetyl)isonicotinohydrazide 10(a-e) were designed, synthesized, characterized, and identified as remarkable anti-inflammatory and analgesic agents. These compounds were prepared in a series of steps starting with different phenol derivatives. Among the series, compound (10e) showed the highest IC50 value for COX-1 inhibition, whereas compounds (9e) and (10e) exhibited the highest COX-2SI. Further, molecular Docking Studies have been performed for the potent compound to check the three-dimensional geometrical view of the ligand binding to the targeted enzymes.

Activator free, expeditious and eco-friendly chlorination of activated arenes by N-chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI)

N-Chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI) has been explored for the first time as a chlorinating reagent for direct chlorination of various activated arenes and heterocycles without any activator. A comparative in-silico study was performed to determine the electrophilic character for NCBSI and commercially available N-chloro reagents to reveal the reactivity on a theoretical viewpoint. The reagent was prepared by an improved method avoiding the use of hazardous t-butyl hypochlorite. This reagent was proved to be very reactive compared to other N-chloro reagents. The precursor of the reagent N-(phenylsulfonyl)benzene sulfonamide was recovered from aqueous spent, which can be recycled to synthesize NCBSI. The eco-friendly protocol was equally applicable for the synthesis of industrially important chloroxylenol as an antibacterial agent.

Preparation method of 2, 4-dichlorophenoxyacetic acid

The invention provides a preparation method of 2, 4-dichlorophenoxyacetic acid, the preparation method comprises the following steps: A) dissolving chloroacetic acid in isopropanol, adding 2, 4-dichlorophenol and polyethylene glycol 400, adding alkali at 10-25 DEG C, and carrying out salt forming reaction; b) after the salt forming reaction is finished, raising the temperature to 80-100 DEG C and carrying out condensation reaction; and C) adding hydrochloric acid into a condensation reaction system for acidification to obtain the 2, 4-dichlorophenoxyacetic acid. The organic solvent isopropanol is adopted, so that wastewater generated by condensation reaction is reduced, the cost is reduced, and the problem of difficult treatment of phenolic wastewater is solved. The catalyst polyethylene glycol 400 is used, the yield is improved, and experimental results show that the yield of the 2, 4-dichlorphenoxyacetic acid prepared by the preparation method is 98%, and the purity is 98.6%.

Novel lipophilic analogues from 2,4-D and Propanil herbicides: Biological activity and kinetic studies

This work describes the synthesis of new lipophilic amides and esters analogues of classical organochlorides herbicides by incorporation of long-chains from fatty acids and derivatives. The new fatty esters and amides were synthesized in 96–99percent and 80–89percent yields, respectively. In general, all compounds tested showed superior in vitro activity than commercial herbicides against growth L. sativa and A. cepa, in ranges 86–100percent of germinative inhibition. The target compounds showed, significantly more susceptible towards acid hydrolysis than 2,4-dichlorophenoxyacetic acid (2,4-D). The kinetic and NMR studies showed that the incorporation of lipophilic chains resulted in a decrease in half-life time of new herbicides compounds (1.5 h) than 2,4-D (3 h). These findings suggest the synthesis of new lipophilic herbicides as potential alternative to traditional formulations, by incorporation of long fatty alkyl chains in the molecular structure of 2,4-D, resulting in superior in vitro herbicidal activity, best degradation behavior and more hydrophobic derivatives.

Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors

A series of aryloxyacetic acid derivatives were designed and synthesized as 4-hydoxyphenylpyruvate dioxygenase (HPPD) inhibitors. Preliminary bioassay results reveal that these derivatives are promising Arabidopsis thaliana HPPD (AtHPPD) inhibitors, in particular compounds I12 (Ki = 0.011 μM) and I23 (Ki = 0.012 μM), which exhibit similar activities to that of mesotrione, a commercial HPPD herbicide (Ki = 0.013 μM). Furthermore, the newly synthesized compounds show significant greenhouse herbicidal activities against tested weeds at dosages of 150 g ai/ha. In particular, II4 exhibited high herbicidal activity for pre-emergence treatment that was slightly better than that of mesotrione. In addition, compound II4 was safe for weed control in maize fields at a rate of 150 g ai/ha, and was identified as the most potent candidate for a novel HPPD inhibitor herbicide. The compounds described herein may provide useful guidance for the design of new HPPD inhibiting herbicides and their modification.

Synthesis method of 2, 4-dichlorophenoxyacetic acid compound

The invention relates to a synthesis method of a 2, 4-dichlorophenoxyacetic acid compound, and relates to the technical field of organic synthesis. The synthesis method of the 2, 4-dichlorophenoxyacetic acid compound is to solve the problems of many by-products existing in synthesis method of the 2, 4-dichlorophenoxyacetic acid compound in prior art, low conversion of phenol, incomplete conversion, environmental pollution resulted, the use of a large number of solvents, production of a large amount of wastewater, high cost, complex technology, high environmental risk, and being not conducive to industrial production. According to the synthesis method of the 2, 4-dichlorophenoxyacetic acid compound, in the synergistic action of anhydrous carbonate weak base and a catalyst, performing condensation of 2, 4-dichlorophenol with halogen acetate, and 2, 4-dichlorophenoxyacetic acid is obtained directly by hydrolysis and acidification. The process of the synthesis method of the 2, 4-dichlorophenoxyacetic acid compound is accomplished by condensation, hydrolysis and acid hydrolysis in one pot without any solvent and using anhydrous carbonate weak base to react with 2, 4-dichlorophenol can effectively inhibit the hydrolysis of chloroacetate, improve the condensation conversion, reduce the content of free phenol, keep a yield over 97% an active ingredient more than 98%, and free phenol content in 50-100 ppm.

Design and Synthesis of Novel 4-Hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one Derivatives for Use as Herbicides and Evaluation of Their Mode of Action

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.

Preparation method of chlorophenoxycarboxylic acid herbicide

The invention provides a preparation method of a chlorophenoxycarboxylic acid herbicide, wherein the preparation method includes the following steps: A) carrying out hydrolysis reaction of chlorophenoxycarboxylic ester under the catalytic action of hydrochloric acid and metal chloride; B) after the reaction is finished, dividing the system into an oil phase and a water phase, and cooling and crystallizing the oil phase, to obtain chlorophenoxycarboxylic acid. Hydrochloric acid and metal chloride are used as a compound catalyst; in the reaction process, the raw material and the catalyst are fully contacted, the reaction rate is increased, the reaction time is shortened, and the reaction is more thorough; after the reaction is finished, the oil phase and the water phase are stratified to facilitate the separation of the product and the catalyst. Excess hydrochloric acid can be evaporated and recycled, water-washing water can be recycled, no waste salt or waste water exists, the energy consumption is low, and the preparation method is economic and environmentally friendly.

Preparation method for 2,4-dichlorophenoxyacetic acid

The invention provides a preparation method for 2,4-dichlorophenoxyacetic acid. The preparation method comprises the following steps: A) reacting 2,4-dichlorophenol with alkali to obtain 2,4-dichlorophenolate and reacting haloacetic acid with an alkali so as to obtain haloacetate; B) reacting the 2,4-dichlorophenolate with the haloacetate so as to obtain 2,4-dichlorophenoxyacetate; and C) mixing 2,4-dichlorophenoxyacetate with acid and carrying out piezocrystallization so as to obtain 2,4-dichlorophenoxyacetic acid, wherein pressurization pressure is 0.1 to 2.0 Mpa. According to the invention,the 2,4-dichlorophenolate and the haloacetate are separately prepared at first and then subjected to a reaction so as to produce the 2,4-dichlorophenoxyacetate; then the 2,4-dichlorophenoxyacetate ismixed with acid; and finally, piezocrystallization is carried out. With such a specific piezocrystallization manner, the prepared 2,4-dichlorophenoxyacetic acid is large in particle size and high inpurity and yield; and dust is not produced during drying and usage, so environment friendliness is achieved.

Preparation method and posttreatment method of chlorophenoxycarboxylic acid herbicide

The invention provides a preparation method of a chlorophenoxycarboxylic acid herbicide, wherein the preparation method includes the following steps: A) carrying out hydrolysis reaction of chlorophenoxycarboxylic ester in water with an acid compound as a catalyst, to obtain a chlorophenoxycarboxylic acid reaction liquid; and crystallizing the reaction liquid by a gradient cooling method comprisingthe steps successively: cooling to 95-80 DEG C, and carrying out stirring heat preservation for 30-90 minutes; cooling to 80-70 DEG C, and carrying out stirring heat preservation for 30-90 minutes; cooling to 70-60 DEG C, and carrying out stirring heat preservation for 30-90 minutes; cooling to 60-50 DEG C, and carrying out stirring heat preservation for 30-90 minutes; cooling to 50-30 DEG C, andcarrying out stirring heat preservation for 30-90 minutes; and cooling to 30 DEG C or less, to obtain chlorophenoxycarboxylic acid crystals and a mother liquor mixture. The method has no waste salt formation, and has the advantages of high conversion rate, recyclable utilization of the catalyst and water, recyclable alcohol, economy and environmental protection. The obtained chlorophenoxycarboxylic acid has the advantages of high purity, large particle size, high bulk density and easy transportation.