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| Synonyms:meta-Dichlorobenzene 1,3-DCB m-DCB Molecular Formula:C6H4Cl2 Molecular Weight: 147 HS Code: 2903999090 Grade: Industrial grade 98% 98.5% 99,99.5% Hazard Class:Class 6.1 | |||||||||
541-73-1
bosschemical
541-73-1
1,3-Dichlorobenzene, also known as m-dichlorobenzene (m-DCB), is a dichlorobenzene isomer with two chlorine atoms on the benzene ring in the meta (1,3) position. It is an important organic synthesis intermediate in the dye and pesticide industries. Its chemical formula is usually written as:
C6H4Cl2 (CAS No.: 541-73-1, EINECS No.: 208-792-1, molecular weight approximately 147.00)
It is a colorless to slightly yellow transparent liquid at room temperature with an aromatic odor. Its melting point is approximately -24°C, boiling point approximately 172-173°C, relative density approximately 1.288 (20°C), refractive index approximately 1.546, and flash point approximately 63-67°C. m-Dichlorobenzene is slightly soluble in water (approximately 123 mg/L) and readily soluble in organic solvents such as ethanol, ether, and benzene. It has a low vapor pressure but a vapor density approximately five times that of air, and will diffuse along the ground.
From a molecular structure perspective, the two chlorine atoms on the benzene ring of m-dichlorobenzene are located in the meta position (positions 1 and 3). These chlorine atoms both withdraw electrons through inductive effects and donate electrons to the benzene ring through p-π conjugation, endowing the molecule with unique electrophilic substitution reactivity. The electron-withdrawing effect of the two chlorine atoms makes specific positions on the benzene ring (such as position 4) more susceptible to electrophilic substitution reactions such as nitration, sulfonation, and amination—this is the structural basis for m-dichlorobenzene to serve as the starting point for the synthesis of a series of fine chemical intermediates.
Chemically, m-dichlorobenzene is stable and does not react with water, but it is flammable and decomposes to produce irritating gases such as hydrogen chloride when burned. It can react violently with active metals such as aluminum, and there is a risk of fire when it comes into contact with strong oxidizers. Therefore, it must be stored and used away from fire sources, oxidizers and active metals.
Industrial-grade m-dichlorobenzene refers to products used in industrial applications such as dyes and pesticide intermediates , with a purity generally above 99.5%. Compared to reagent-grade products, industrial-grade products place greater emphasis on the following indicators:
Content (purity)
Industrial-grade main components generally require a content of 99.5% or higher, as the content determines the yield of downstream intermediate synthesis and product quality.
Isomer content (o-dichlorobenzene, p-dichlorobenzene)
Dichlorobenzene has three isomers. The content of the ortho and para isomers in m-dichlorobenzene must be strictly controlled, otherwise it will significantly affect the purity and selectivity of downstream reactions.
Moisture
Moisture content affects the reaction system and storage stability, and must be strictly controlled.
acidity
Excessive levels of free acid (such as hydrogen chloride) can corrode equipment and affect subsequent reactions, making it an important quality indicator.
Color (APHA)
The color should be colorless to slightly yellow. Abnormal color often indicates oxidation or process impurities, which will affect the appearance of downstream products.
Industrial-grade m-dichlorobenzene is a typical "intermediate of intermediates," with its applications concentrated in downstream sectors such as dyes and pesticides.
The dye industry is the largest application area for m-dichlorobenzene, accounting for approximately 40% of total consumption. m-Dichlorobenzene is an important intermediate in the synthesis of azo dyes and anthraquinone dyes (such as m-aminophenol and resorcinol), and is subsequently used for dyeing textiles, leather, and paper.
The pesticide industry accounts for about 30% of the consumption of dichlorobenzene. It is an important synthetic raw material for fungicides such as propiconazole, difenoconazole, imidacloprid, hexaconazole, eticonazole, and insecticides such as chlorpyrifos, serving the disease control of modern agriculture.
m-Dichlorobenzene has good solubility and stable chemical properties, and can be used as a solvent and reaction medium for organic synthesis reactions to help dissolve reactants, adjust reaction conditions, and serve fine chemical production.
m-Dichlorobenzene can be oxidized through reactions such as nitration, amination, and sulfonation to produce important fine chemicals such as resorcinol, m-aminophenol, m-phenylenediamine, and m-chloroaniline, which are used in downstream industries such as dyes and rubber additives.
High-purity m-dichlorobenzene is used as a reagent in chemical research and as a standard substance in environmental analysis. It is used for environmental monitoring, occupational exposure assessment and the development of chromatographic analysis methods, and is an important object of environmental and occupational health research.
With the development of new pesticide and dye products, the application scope of industrial-grade m-dichlorobenzene continues to expand, including in areas such as specialty chemical synthesis and solvent recycling.
It should be noted that industrial grade specifications do not mean "risk-free": m-dichlorobenzene is a flammable liquid, its vapor is heavier than air, and inhalation of the vapor or skin contact is harmful. Handling must be carried out in a well-ventilated area with protective equipment worn. Storage must be kept away from fire sources, oxidizers and active metals, and contact with food is strictly prohibited.
1,3-Dichlorobenzene (m-dichlorobenzene) (CAS No. 541-73-1) is a colorless to slightly yellow chloroaromatic liquid with a boiling point of about 173 deg C. The two chlorine atoms are situated in the meta position of the benzene ring, leading to a unique electrophilic substitution reactivity. It is an important intermediate in the dye and pesticide industry. In daily life we have indirect contact with it via the chain of pesticide residues in fruit and vegetables, dyes and textiles, quality of ambient air and water, chemical logistics, and testing laboratories. In industrial use, m-dichlorobenzene of purity >99.5% is widely employed as an intermediate for azo dyes and anthraquinone dyes, as an intermediate for pesticide fungicides such as propiconazole, as a solvent in synthesis of organic compounds, and in the production of fine chemicals such as resorcinol. It is a significant intermediate between "chloroaromatic hydrocarbons" and "dyes, pesticides and fine chemicals".
