General Description
DICHLONE(117-80-6) is a yellow crystalline solid dissolved in a water-emulsifiable liquid carrier. Can cause illness by inhalation, skin absorption and/or ingestion. The primary hazard is the threat to the environment. Immediate steps should be taken to limit its spread to the environment. Can easily penetrate the soil and contaminate groundwater and nearby streams. Used as a fungicide.
Reactivity Profile
DICHLONE is a halogenated ketone. Ketones are reactive with many acids and bases liberating heat and flammable gases (e.g., H2). The amount of heat may be sufficient to start a fire in the unreacted portion of the ketone. Ketones react with reducing agents such as hydrides, alkali metals, and nitrides to produce flammable gas (H2) and heat. Ketones are incompatible with isocyanates, aldehydes, cyanides, peroxides, and anhydrides. They react violently with aldehydes, HNO3, HNO3 + H2O2, and HClO4.
Air & Water Reactions
Insoluble in water.
Health Hazard
INHALATION: Irritation to mucous membrane. EYES: Irritation. SKIN: Irritation. INGESTION: Can cause CNS depression.
Fire Hazard
Special Hazards of Combustion Products: Highly toxic fumes are imminent.
Description
Dichlone is an obsolete foliar fungicide. It has a low aqueous solubility and is not mobile and, based on its chemical properties, it is unlikely to leach to groundwater. It is not persistent in most soil systems. Dichlone has a moderate mammalian toxicity. Little has been reported regarding its toxicity to biodiversity.
Chemical Properties
YELLOW FINE CRYSTALLINE POWDER
Uses
Fungicide for agriculture and textiles; herbicide.
Uses
Fungicide used on fruits, field crops and vegetables
Production Methods
The commercial production of diclone follows a concise two-step chlorination-oxidation process. First, 1,4-naphthoquinone is chlorinated with chlorine gas in glacial acetic acid or chlorobenzene using iodine or FeCl₃ as catalyst, adding two chlorine atoms selectively at the 2,3-positions to form crude 2,3-dichloro-1,4-naphthoquinone. The product is isolated by filtration after cooling, washed with water and methanol, and recrystallised from toluene or acetone to technical-grade diclone,
Flammability and Explosibility
Notclassified
Agricultural Uses
Fungicide: Not currently registered in the U.S. Not approved for
use in the EU. Dichlone is used as a fungicide for foliage
and to control blue algae in ponds, swimming pools and
lakes. As a substitute for copper and sulfur to control rot on
fruit trees, vegetables, field crops, ornamentals, resident
and commercial outdoor areas.
Trade name
ALGISTAT®; COMPOUND 604®;
PHYGON®; PHYGON® PASTE; PHYGON® SEED
PROTECTANT; PHYGON® XL; QUINTAR®;
QUINTAR® 540F; SANQUINON®; UNIROYAL® 604;
USR® 604; U.S. RUBBER® 604
Mechanism of action
Foliar with protective action by disrupting fungal enzyme activity. It interferes with electron transport in fungal cells, leading to oxidative stress and cell damage,
Environmental Fate
Plant. In plants, dichlone loses both chlorine atoms and are replaced by sulphydryl
groups to give a substituted dimercapto compound (Hartley and Kidd, 1987).
Photolytic. The UV absorption band for dichlone is 330 nm (Gore et al., 1971).
Irradiation of dichlone in a variety of organic solvents (benzene, isopropanol, ethanol)
using UV light produced a number of dehalogenated compounds. In the absence or
presence of oxygen, 2-chloro-1,4-naphthoquinone, 1,4-naphthoquinone and 1,4-naphthalenediol
were produced. Further irradiation in the presence of oxygen yielded phthalic
acid and phthalic anhydride as the major products. In a mixture of benzene and isopropanol,
dichlone degraded to the minor products: 2-chloro-3-hydroxy-1,4-naphthoquinone, 2-
chloro-3-phenoxy-1,4-naphthoquinone, 2,3-dichloro-4-hydroxy-1-keto-2-phenyl-1,2-
dihydronaphthalene and isopropyl-1-chloro-2,3-dioxo-1-indanecarboxylate (Ide et al.,
1979).
Chemical/Physical. Emits toxic fumes of chlorine when heated to decomposition (Sax
and Lewis, 1987).
Purification Methods
Crystallise the quinone from EtOH. [Beilstein 7 IV 2426.]
Pesticide Type
Fungicide; Algicide
