2-МЕТИЛ-4-ХЛОРОФЕНОКСИУКСУСНАЯ КИСЛОТА

Химические свойства

White, crystalline solid. Free acid insoluble in water but sodium and amine salts are soluble.

Использование

Labelled MCPA (C369470). Herbicide.

Определение

ChEBI: A chlorophenoxyacetic acid that is (4-chlorophenoxy)acetic acid substituted by a methyl group at position 2.

Общее описание

Colorless plates. Corrosive. Practically insoluble in water. Used as an herbicide.

Реакции воздуха и воды

Insoluble in water.

Сельскохозяйственное использование

Herbicide: A U.S. EPA restricted Use Pesticide (RUP) as MCPA, sodium salt. MCPA is a systemic post-emergence phenoxy herbicide used to control broadleaf annual and perennial weeds (including thistle and dock) in cereals, flax, rice, vines, peas, potatoes, grasslands, forestry applications, and on rights-of-way. It is very compatible with many other compounds and may be used in formulation with many other products, including bentazone, bromoxynil, 2,4-D, dicamba, fenoxaprop, MCPB, mecoprop, thifensulfuron, and tribenuron.

Торговое название

ACME MCPA AMINE 4®; AGRITOX®; AGROXONE®; AGROZONE®; AGSCO®; ANICON KOMBI®; ANICON M®; BANLENE®; BLESEL MC®; BORDERMASTER®; BROMINAL M & PLUS®; CAMBILENE®; CHEYENNE®; CHIMAC OXY®; CHIPTOX®; CHWASTOX®; CORNOX M®; DAKOTA®; DED WEED®; DICOPUR-M®; DICOTEX®; DOW MCP AMINE WEED KILLER®; DYVEL®; EH1356 HERBICIDE®; EMCEPAN®; EMPAL®; ENVOY®; HEDAPUR M 52®; HEDAREX M®; HEDONAL M®; HERBICIDE M®; HORMOTUHO®; HORNOTUHO®; KILSEM®; 4 K-2 M®; KVK®; LEGUMEX DB®; LEUNA M®; LEYSPRAY®; LINORMONE®; M 40®; 2 M-4C®; 2 M-4KH®; MALERBANE®; MAYCLENE®; MEPHANAC®; MIDOX®; MXL®; OKULTIN®; PHENOXYLENE 50®; PHENOXYLENE PLUS®; PHENOXYLENE SUPER®; RAZOL DOCK KILLER®; RHOMENE®; RHONOX®; SHAMOX®; B-SELEKTONON M®; SEPPIC MMD®; TILLER®; TRIMEC®; U 46®; VACATE®; VESAKONTUHO®; WEEDAR®; WEEDAR MCPA CONCENTRATE®; WEEDONE MCPA ESTER®; WEED RHAP®; ZELAN®

Профиль безопасности

Suspected carcinogen. Poison by subcutaneous and intravenous routes. Moderately toxic by ingestion. Human systemic effects by ingestion: blood pressure decrease and coma. Experimental teratogenic and reproductive effects. Mutation data reported. An herbicide. When heated to decomposition it emits toxic fumes of Cl-.

Возможный контакт

A potential danger to those involved in the manufacture, formulation, and application of this postemergence herbicide, used for control of broadleaf weeds in agricultural applications.

Экологическая судьба

Biological. Cell-free extracts isolated from Pseudomonas sp. in a basal salt medium degraded MCPA to 4-chloro-o-cresol and glyoxylic acid (Gamar and Gaunt, 1971).
Soil. Residual activity in soil is limited to approximately 3–4 months (Hartley and Kidd, 1987).
Plant. The penetration, translocation and metabolism of radiolabeled MCPA in a cornland weed (Galium aparine) was studied by Leafe (1962). Carbon dioxide was identified as a metabolite but this could only account 7% of the applied MCPA. Though no
Photolytic. When MCPA in dilute aqueous solution was exposed to summer sunlight or an indoor photoreactor (l >290 nm), 2-methyl-4-chlorophenol formed as the major product as well as o-cresol and 4-chloro-2-formylphenol (Soderquist and Crosby, 1975). Clapés et al. (1986) studied the photodecomposition of aqueous solution of MCPA (120 ppm, pH 5.4, 25°C) in a photoreactor equipped with a high pressure mercury lamp. After three minutes of irradiation, 4-chloro-2-methylphenol formed as an intermediate which degraded to 2-methylphenol. Both compounds were not detected after 6 minutes of irradiation; however, 1,4-dihydroxy-2-methylbenzene and 2-methyl-2,5-cyclohexadiene-1,4- dione formed as major and minor photodecomposition products, respectively. The same experiment was conducted using simulated sunlight (l <300 nm) in the presence of riboflavin, a known photosensitizer. 4-Chloro-2-methylphenol and 4-chloro-2-methylbenzyl formate formed as major and minor photoproducts, respectively (Clapés et al., 1986). Ozone degraded MCPA in dilute aqueous solution with and without UV light (l >300 nm) (Benoit-Guyod et al., 1986).
Chemical/Physical. Reacts with alkalies forming water soluble salts (Hartley and Kidd, 1987). Ozonolysis of MCPA in the dark yielded the following benzenoid intermediates: 4-chloro-2-methylphenol, its formate ester, 5-chlorosalicyaldehyde, 5-chlo

Перевозки

UN3345 Phenoxyacetic acid derivative pesticide, solid, toxic, Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required

Методы очистки

It is insoluble in H2O (solubility is 0.55g/L at 20o) and recrystallises from *C6H6 or chlorobenzene as plates [J.nsson et al. Acta Chem Scand 6 993 1952]. The S-benzylisothiouronium salt has m 164-165o, and the Cu2+ salt has m 247-249o(dec) [Armarego et al. Nature 183 1176 1959, UV: Duvaux & Grabe Acta Chem Scand 4 806 1950, IR: J.berg Acta Chem Scand 4 798 1950]. [Beilstein 6 IV 1991.] It is a plant growth substance and a herbicide.

Несовместимости

A weak acid. Compounds of the carboxyl group react with all bases, both inorganic and organic (i.e., amines) releasing substantial heat, water and a salt that may be harmful. Incompatible with arsenic compounds (releases hydrogen cyanide gas), diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides (releasing heat, toxic, and possibly flammable gases), thiosulfates and dithionites (releasing hydrogen sulfate and oxides of sulfur). Incompatible with alkalis.

Утилизация отходов

Incineration with added flammable solvent; incinerator equipped with fume scrubber. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office