Chemical Properties
There are three isomeric forms of dichlorobenzene (DCB):
m-DCB is a flammable liquid and vapor.
Physical properties
1,3-Dichlorobenzene is a clear, colorless liquid with a disinfectant or musty-type odor. Soluble in alcohol, ether, insoluble in water. At 40 °C, the average odor threshold concentration and the lowest concentration at which an odor was detected were 170 and 177 μg/L, respectively. At 25 °C, the lowest concentration at which a taste was detected was 190 μg/L, respectively (Young et al., 1996).
Uses
1,3-Dichlorobenzene is used in organic synthesis that can synthesize fungicides imazalil, propiconazole, epiconazole, and insecticides insectaphos. It is also used in the synthesis of 1,2-diaminobenzene, in addition, it is also used as a solvent in the fields of dyes, medicine, resin, rubber and so on.
Uses
1,3-Dichlorobenzene is used in medicine, and dyes. And it is also used to study the effect of solvent vapor pressure on the vertical nanowire of C60 molecules1. 1,3-Dichlorobenzene, a chlorinated aromatic hydrocarbon, can be detected in environmental samples using an advanced Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) sensor.
Application
1,3-Dichlorobenzene was used to study the effect of solvent vapor pressure on the vertical nanowire of C60 molecules. 1,3-Dichlorobenzene, a chlorinated aromatic hydrocarbon, can be detected in environmental samples using an advanced Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) sensor.
Definition
ChEBI: 1,3-dichlorobenzene is a dichlorobenzene carrying chloro substituents at positions 1 and 3. Used as a fumigant, insecticide, and chemical intermediate.
Preparation
1,3-Dichlorobenzene is prepared from o-chloroaniline through diazotization and displacement reaction.
Add o-chloroaniline and hydrochloric acid into the reaction pot, mix evenly below 25°C, cool to 0°C, drop in sodium nitrite solution, control the temperature at 0-5°C, stop adding when the potassium iodide starch indicator turns blue, and obtain diazonium salt solution. Then add the diazonium salt solution into the hydrochloric acid solution of cuprous chloride at 0～5℃, stir well, heat up to 60～70℃ and react for 1h, after cooling, let stand for stratification, and use 5% sodium hydroxide for the oil layer. Repeated washing with water, dehydration with anhydrous calcium chloride, fractional distillation, and collection of fractions at 177-183 °C to obtain the product 1,3-dichlorobenzene.
Synthesis Reference(s)
The Journal of Organic Chemistry, 48, p. 250, 1983
DOI: 10.1021/jo00150a020
General Description
Colorless liquid. Sinks in water.
Air & Water Reactions
1,3-Dichlorobenzene is sensitive to moisture. Insoluble in water.
Reactivity Profile
1,3-Dichlorobenzene is incompatible with oxidizing agents and aluminum and its alloys. Above the flash point, explosive vapor-air mixtures may be formed.
Health Hazard
INHALATION: Causes headache, drousiness, unsteadiness. Irritating to mucous membranes. EYES: Severe irritation. SKIN: Severe irritation. INGESTION: Irritation of gastric mucosa, nausea, vomiting, diarrhea, abdominal cramps and cyanosis.
Fire Hazard
Special Hazards of Combustion Products: Irritating vapors including hydrogen chloride are produced.
Flammability and Explosibility
Flammable
Safety Profile
Moderately toxic by
intraperitoneal route. Mutation data
reported. When heated to decomposition it
emits toxic fumes of Cl-. See also oDICHLOROBENZENE and p
DICHLOROBENZENE.
Potential Exposure
The major uses of o-DCB are as
a process solvent in the manufacturing of toluene diisocyanate and as an intermediate in the synthesis of dyestuffs,
herbicides, and degreasers. p-Dichlorbenzene is used
primarily as a moth repellant, a mildew control agent;
space deodorant; and in insecticides, which accounts for
90% of the total production of this isomer. Information is
not available concerning the production and use of m-DCB.
However, it may occur as a contaminant of o-or p-DCB
formulations. Both o-and p-isomers are produced almost
entirely as by-products during the production of
monochlorobenzene
Environmental Fate
Biological. When 1,3-dichlorobenzene was statically incubated in the dark at 25 °C with yeast
extract and settled domestic wastewater inoculum, significant biodegradation with gradual
acclimation was followed by a deadaptive process in subsequent subcultures. At a concentration of
5 mg/L, 59, 69, 39, and 35% losses were observed after 7, 14, 21, and 28-d incubation periods,
respectively. At a concentration of 10 mg/L, percent losses were virtually unchanged. After 7, 14,
21, and 28-d incubation periods, percent losses were 58, 67, 31, and 33, respectively (Tabak et al.,
1981).
Photolytic. The sunlight irradiation of 1,3-dichlorobenzene (20 g) in a 100-mL borosilicate
glass-stoppered Erlenmeyer flask for 56 d yielded 520 ppm trichlorobiphenyl (Uyeta et al., 1976).
Chemical/Physical. Anticipated products from the reaction of 1,3-dichlorobenzene with
atmospheric ozone or OH radicals are chlorinated phenols, ring cleavage products, and nitro
compounds (Cupitt, 1980). Based on an assumed base-mediated 1% disappearance after 16 d at 85
oC and pH 9.70 (pH 11.26 at 25 oC), the hydrolysis half-life was estimated to be >900 yr
(Ellington et al., 1988). 1,3-Dichlorobenzene (0.17–0.23 mM) reacted with OH radicals in water
(pH 8.7) at a rate of 5.0 x 10
9/M·sec (Haag and Yao, 1992).
Shipping
m-DCB: UN2810 Toxic liquids, organic, n.o.s.,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials,
Technical Name Required. United States DOT Regulated
Marine Pollutant. UN3077 Environmentally hazardous
substances, solis, n.o.s., Hazard class: 9; Labels:
9-Miscellaneous hazardous material, Technical NameRequired. UN3082 Environmentally hazardous substances,
liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required
Purification Methods
Wash it with aqueous 10% NaOH, then with water until neutral, dry and distil it. Conductivity material (ca 10-10 mhos) has been prepared by refluxing over P2O5 for 8hours, then fractionally distilling, and storing with activated alumina. m-Dichlorobenzene dissolves rubber stoppers. [Beilstein 5 IV 657.]
Incompatibilities
For o-DCB and m-DCB: acid fumes,
chlorides, strong oxidizers; hot aluminum, or aluminum
alloys. For p-DCB: Strong oxidizers; although, incompatibilities for this chemical may also include other materials
listed for o-DCB.
Waste Disposal
Incineration, preferably
after mixing with another combustible fuel. Care must be
exercised to assure complete combustion to prevent
the formation of phosgene. An acid scrubber is necessary
to remove the halo acids produced. 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
