Name | 2,4-Dichlorophenoxybutyric acid |
Synonyms | butyrac118 butyrac200 butyracester 2,4-D Butyric 2,4-D butyric acid Campbell's db straight 2,4-Dichlorophenoxybutyric acid butyricacid,4-(2,4-dichlorophenoxy)- Butyric acid, 4-(2,4-dichlorophenoxy)- |
CAS | 94-82-6 |
EINECS | 202-366-9 |
Molecular Formula | C10H10Cl2O3 |
Molar Mass | 249.09 |
Density | 1.3342 (estimate) |
Melting Point | 118-120°C(lit.) |
Boling Point | 324.35 °C |
Water Solubility | 53mg/L(room temperature) |
Appearance | Amorphous Powder |
Color | Off-white |
Merck | 13,2855 |
BRN | 1976809 |
pKa | 4.56±0.10(Predicted) |
Storage Condition | 0-6°C |
Physical and Chemical Properties | The pure product is a colorless oily liquid. B. p.169 ℃/266Pa, 146~147 ℃/133.2Pa (original drug), m.p.9 ℃, flash point above 48 ℃, relative density 1.2428. Soluble in a variety of organic solvents, insoluble in water, highly volatile. It is stable to acid and heat, and is decomposed into 2,4-drops of sodium salt and butanol in case of alkali. Industrial products are brown and have a phenol odor. |
Risk Codes | R22 - Harmful if swallowed R51/53 - Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. |
Safety Description | S25 - Avoid contact with eyes. S29 - Do not empty into drains. S46 - If swallowed, seek medical advice immediately and show this container or label. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. |
UN IDs | UN 3077 9/PG 3 |
WGK Germany | 2 |
RTECS | ES9100000 |
HS Code | 29189900 |
Hazard Class | 6.1(b) |
Packing Group | III |
NIST chemical information | Information provided by: webbook.nist.gov (external link) |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
use | broad-spectrum, hormonal herbicide, with good spreading and absorption. It is usually used in paddy fields and wheat fields, etc., mainly to control dicotyledonous weeds, heterosexual saxaceae and certain malignant weeds in gramineous crop fields, such as duck tongue grass, eye seed, small three-sided grass, polygonum, beak Niang, ragweed, wild amaranth, quinoa, etc. |
production method | synthesis of 2,4-drops first synthesizes sodium phenol and sodium chloroacetate, then the two are condensed, and the reaction is carried out at 110~120 ℃. the reaction process maintains the slightly alkaline solution, and the feed ratio of monochloroacetic acid to phenol is 1:1.16. Then the chlorination reaction is carried out, chlorine gas is used as chlorinating agent, and the reaction temperature is 92~98 ℃. It is also reported that the following operation methods are adopted: after 31.6g(0.332mol) of industrial phenol is mixed with a proper amount of toluene, the temperature is raised to the near reflux point, sodium hydroxide and chloroacetic acid aqueous solution are added dropwise at the reflux temperature for 1h, 230mL of tap water is added after the reaction, and the organic phase solvent is separated and recycled to obtain phenoxyacetic acid, which is directly used for chlorination reaction without distillation operation. Chlorine is used as chlorinating agent. Add trace catalyst (such as iodine powder), chlorination time is 1~3.5h, chlorination temperature is 65~90 ℃, chlorination is finished, filtration and washing at room temperature, drying to obtain 2,4-D 57.0g, the total yield of the two steps is ≥ 76%, and the quality is obviously improved. Synthesis of 2,4-Drop Butyl Add wet 2,4-drops to quantitative butanol under stirring, raise the temperature to 120~140 ℃, keep it for 4 hours, fully dehydrate, and butanol refluxes. When the water surface of the separator no longer rises, stop backflow, raise the temperature to 160~170 ℃, and evaporate butanol under reduced pressure. |
category | pesticide |
toxicity classification | poisoning |
acute toxicity | oral-rat LD50: 700 mg/kg |
flammability hazard characteristics | combustion produces toxic chloride gas |
storage and transportation characteristics | warehouse ventilation and low temperature drying; separate from food raw materials storage and transportation |
fire extinguishing agent | dry powder, foam, sand |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |