2,3-Dichlorotoluene: Properties, Handling & Lab Use Guide

2,3-Dichlorotoluene is a chlorinated aromatic hydrocarbon widely used as a synthetic intermediate and reference standard in organic chemistry and analytical research.

CAS Number

32768-54-0

Molecular Formula

C₇H₆Cl₂

Molecular Weight

161.03 g/mol

Appearance

Colorless to pale yellow liquid

Boiling Point

Approx. 208 °C (literature value; verify with SDS)

Purity (Aladdin SKU D113531)

See product specification sheet

Storage Condition

Room temperature, away from heat and ignition sources; keep container tightly sealed

Chemical Identity and Physical Properties

2,3-Dichlorotoluene (CAS 32768-54-0) is a dihalogenated aromatic compound in which two chlorine atoms occupy the 2- and 3-positions of the toluene ring, with the methyl group at position 1. Its molecular formula is C₇H₆Cl₂ and its molecular weight is approximately 161.03 g/mol. The compound exists as a colorless to pale yellow liquid at room temperature with a characteristic aromatic odor.

Key physical constants reported in the literature include a boiling point of approximately 208 °C and a density greater than water, consistent with other polychlorinated toluene isomers. Its relatively low water solubility and moderate vapor pressure are important considerations for laboratory handling and environmental fate. Researchers should consult the Aladdin product specification sheet and the accompanying Safety Data Sheet (SDS) for lot-specific purity data and up-to-date physical constants, as values can vary between sources.

Laboratory Applications and Synthesis Utility

2,3-Dichlorotoluene serves primarily as a building block and synthetic intermediate in organic chemistry. The two electronegative chlorine substituents on the aromatic ring activate it toward nucleophilic aromatic substitution (SNAr) reactions under appropriate conditions, and the methyl group can be further functionalized via side-chain oxidation, halogenation, or radical reactions to yield diverse derivatives.

Common downstream synthetic targets include dichlorobenzoic acids, dichlorobenzyl halides, and more complex heterocyclic or biaryl systems prepared through transition-metal-catalyzed cross-coupling reactions such as Suzuki, Kumada, or Negishi couplings. The compound is also used as an analytical reference standard in environmental monitoring studies of chlorinated aromatic pollutants and in method development for gas chromatography (GC) and high-performance liquid chromatography (HPLC).

Researchers working in agrochemical, pharmaceutical, and materials-science discovery programs may employ 2,3-Dichlorotoluene as a starting material when a specific ortho-relationship between the two halogen substituents is required for downstream cyclization or directed metalation strategies.

Safe Handling, Storage, and Waste Disposal

Personal Protective Equipment (PPE): Always wear appropriate chemical-resistant gloves (e.g., nitrile), safety goggles or a face shield, and a laboratory coat when handling 2,3-Dichlorotoluene. Work in a well-ventilated fume hood to minimize inhalation exposure to vapors.

Storage: Store the compound at room temperature in a tightly sealed container, away from heat sources, open flames, and incompatible oxidizing agents. Keep away from direct sunlight. Follow institutional storage regulations for flammable or combustible organic liquids.

Spill Response: In the event of a spill, ventilate the area immediately, evacuate non-essential personnel, and absorb the liquid with inert material (e.g., vermiculite or dry sand). Collect waste in a labeled, closed container for disposal as halogenated organic waste.

Waste Disposal: Dispose of 2,3-Dichlorotoluene and contaminated materials in accordance with local, national, and institutional regulations governing halogenated organic waste. Do not pour down the drain. Consult your institution's Environmental Health and Safety (EHS) office for approved disposal procedures.

Note: Always consult the current Aladdin Safety Data Sheet (SDS) for D113531 before use, as it contains the most authoritative and up-to-date hazard information.

Quality, Purity, and Regulatory Considerations

For reproducible experimental results, the purity and isomeric integrity of 2,3-Dichlorotoluene are critical. The dichlorotoluene family comprises six positional isomers; contamination with adjacent isomers (e.g., 2,4- or 2,5-dichlorotoluene) can affect reaction selectivity and analytical accuracy. Aladdin's D113531 is supplied with a product specification sheet detailing purity, analytical method, and lot-specific data — researchers should review this documentation prior to use.

For GC-purity-sensitive applications, a pre-use GC analysis is recommended to confirm isomeric purity. NMR spectroscopy (¹H and ¹³C) can also be used to confirm the regiochemical identity of the compound based on the characteristic aromatic and methyl proton chemical shifts consistent with the 2,3-substitution pattern.

From a regulatory perspective, chlorinated aromatic compounds may be subject to chemical inventory and reporting requirements under frameworks such as REACH (EU) or TSCA (US). Users should verify current regulatory status in their jurisdiction before ordering or using large quantities.

Frequently asked questions

What is the difference between 2,3-Dichlorotoluene and other dichlorotoluene isomers?

2,3-Dichlorotoluene has chlorine atoms at the 2- and 3-positions (adjacent/ortho to each other) relative to the methyl group, giving it a distinct electronic and steric profile compared to other isomers such as 2,4-, 2,5-, 2,6-, 3,4-, or 3,5-dichlorotoluene. This specific substitution pattern dictates its reactivity in directed metalation, cross-coupling, and nucleophilic aromatic substitution reactions, and makes it non-interchangeable with other isomers for most synthetic purposes. GC or NMR analysis is recommended to confirm isomeric identity before use in sensitive applications.

How should 2,3-Dichlorotoluene be stored to maintain stability?

2,3-Dichlorotoluene should be stored in a tightly sealed container at room temperature, away from heat, open flames, strong oxidizing agents, and direct sunlight. Ensuring the container is properly sealed prevents evaporative loss and moisture ingress, both of which can affect purity over time. Always refer to the current Aladdin SDS for D113531 for the most complete and up-to-date storage instructions.

Can 2,3-Dichlorotoluene be used as an analytical reference standard?

Yes, 2,3-Dichlorotoluene is suitable for use as an analytical reference standard in methods such as GC and HPLC, particularly in environmental analysis of chlorinated aromatic compounds. For this purpose, the purity of the compound is paramount; researchers should verify lot-specific purity data from the Aladdin certificate of analysis (CoA) for D113531 to ensure the material meets the requirements of their method.

Is 2,3-Dichlorotoluene hazardous, and what PPE is required?

Like most chlorinated aromatic compounds, 2,3-Dichlorotoluene poses potential health and environmental hazards including skin and eye irritation and vapor inhalation risks. Appropriate PPE includes chemical-resistant gloves (nitrile recommended), safety goggles, and a lab coat; all handling should be conducted in a fume hood. Consult the SDS for D113531 available from Aladdin for full GHS hazard classification, first-aid measures, and exposure limits before use.

References

1. Aladdin Scientific. Product Specification Sheet: 2,3-Dichlorotoluene, SKU D113531. Aladdin Scientific.
2. Aladdin Scientific. Safety Data Sheet (SDS): 2,3-Dichlorotoluene, SKU D113531. Aladdin Scientific.
3. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. 4th ed. Wiley-Interscience, 1992. (General reference for aromatic substitution chemistry.)
4. Royal Society of Chemistry. ChemSpider entry for 2,3-Dichlorotoluene (CAS 32768-54-0). RSC.

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