1-Chloro-3-iodo-2-nitrobenzene: Properties & Lab Use

1-Chloro-3-iodo-2-nitrobenzene is a polyhalogenated nitroaromatic building block widely used in organic synthesis, particularly as a selective electrophilic partner in transition-metal-catalyzed cross-coupling reactions and nucleophilic aromatic substitution chemistry.

IUPAC Name

1-Chloro-3-iodo-2-nitrobenzene

SKU

C188417

Molecular Formula

C₆H₃ClINO₂

Molecular Weight

283.45 g/mol

Functional Groups

Aryl chloride, aryl iodide, nitro group

Primary Application

Cross-coupling reactions, nucleophilic aromatic substitution, pharmaceutical intermediates

Chemical Identity and Structure

1-Chloro-3-iodo-2-nitrobenzene (SKU: C188417) is a trisubstituted benzene ring bearing a chloro group at the 1-position, an iodo group at the 3-position, and a nitro group at the 2-position. The molecular formula is C₆H₃ClINO₂ with a molecular weight of approximately 283.45 g/mol. The presence of both a chlorine and an iodine substituent on the same ring confers significant synthetic versatility, since these two halogens display markedly different reactivity profiles toward palladium- and copper-catalyzed cross-coupling protocols. The electron-withdrawing nitro group positioned ortho to the chloro substituent further activates the ring toward nucleophilic aromatic substitution (SNAr) at the C-1 position.

Reactivity and Synthetic Applications

The differential reactivity between the C–I and C–Cl bonds is the central synthetic asset of 1-chloro-3-iodo-2-nitrobenzene. Carbon–iodine bonds are substantially more reactive than carbon–chlorine bonds under standard palladium-catalyzed conditions (e.g., Suzuki–Miyaura, Sonogashira, Negishi, and Heck reactions), enabling selective functionalization at the 3-position while preserving the C–Cl bond for subsequent transformations. This orthogonal reactivity allows chemists to perform sequential cross-coupling sequences, attaching two different substituents in a controlled order on the same aromatic scaffold.

Concurrently, the ortho-nitro group strongly activates the C–Cl bond toward SNAr reactions with nitrogen, oxygen, and sulfur nucleophiles, providing an additional, metal-free route to further diversification. The nitro group may also be reduced to an amine at a late stage, opening access to aminobenzene derivatives and condensed heterocycles such as indoles, benzimidazoles, and anthranils. These combined attributes make this reagent particularly valuable in medicinal chemistry, agrochemical synthesis, and materials science.

Handling, Storage, and Safety

As with most polyhalogenated nitroaromatic compounds, 1-chloro-3-iodo-2-nitrobenzene should be treated as a potential irritant and handled with appropriate personal protective equipment, including nitrile gloves, safety goggles, and a lab coat. Work should be conducted in a well-ventilated fume hood to minimize inhalation of dust or vapors. The compound should be stored in a cool, dry place away from strong reducing agents, bases, and heat sources. Consult the current Safety Data Sheet (SDS) supplied by Aladdin Scientific for precise hazard classifications, first-aid measures, and disposal guidance before use.

For long-term stability, storage under inert atmosphere (nitrogen or argon) at or below room temperature in a tightly sealed container is recommended. Avoid exposure to moisture, which can potentially promote slow hydrolytic side reactions over extended storage periods.

Purity, Specifications, and Quality Assurance

Aladdin Scientific supplies 1-chloro-3-iodo-2-nitrobenzene (C188417) to research-grade purity standards. Researchers should consult the product page or Certificate of Analysis (CoA) for the specific lot purity value, which is typically confirmed by techniques such as GC, HPLC, or NMR. For sensitive synthetic applications, particularly those involving catalytic cross-coupling where trace metal or regioisomeric impurities can affect yield and selectivity, it is advisable to verify purity via an independent analytical method prior to use. Aladdin Scientific's quality control procedures are designed to ensure batch-to-batch consistency, and lot-specific CoA documents are available upon request.

Ordering and Availability

1-Chloro-3-iodo-2-nitrobenzene is available from Aladdin Scientific under SKU C188417. To place an order, visit the Aladdin Scientific website, search by product name or SKU, and select the desired quantity. For bulk or custom quantities, institutional pricing, or supply agreements, contact the Aladdin Scientific sales team directly. Standard shipping conditions apply; please review the shipping and delivery policy for reagents requiring specific temperature controls or hazardous-material shipping documentation in your region.

Frequently asked questions

What makes 1-chloro-3-iodo-2-nitrobenzene useful in cross-coupling chemistry?

The compound contains both a C–I and a C–Cl bond on the same aromatic ring. Under standard palladium-catalyzed conditions, the C–I bond reacts preferentially, allowing selective functionalization at the 3-position while the C–Cl bond is preserved for a second, independent coupling step. This orthogonal reactivity enables the sequential introduction of two different groups onto a single aromatic scaffold.

Can the nitro group in 1-chloro-3-iodo-2-nitrobenzene be reduced to an amine?

Yes. The aromatic nitro group can be reduced to a primary amine using standard methods such as catalytic hydrogenation (H₂/Pd-C) or chemical reductants (e.g., iron/acetic acid, tin(II) chloride). The resulting aniline intermediate can then be used to construct heterocyclic frameworks such as indoles or benzimidazoles, broadening the synthetic utility of this building block.

How should 1-chloro-3-iodo-2-nitrobenzene be stored to maintain stability?

Store the compound in a tightly sealed container under an inert atmosphere (nitrogen or argon) in a cool, dry location away from light, moisture, and strong reducing agents. These conditions minimize the risk of slow decomposition or hydrolytic side reactions during prolonged storage. Always consult the Aladdin Scientific SDS for the most current storage recommendations.

Is 1-chloro-3-iodo-2-nitrobenzene suitable for nucleophilic aromatic substitution (SNAr)?

Yes. The electron-withdrawing nitro group at the 2-position strongly activates the adjacent C–Cl bond toward SNAr with nucleophiles such as amines, alkoxides, and thiolates. This provides a complementary, metal-free pathway for ring functionalization that can be employed independently of or in sequence with cross-coupling steps.

How do I obtain a Certificate of Analysis (CoA) for C188417?

Lot-specific Certificates of Analysis for C188417 are available from Aladdin Scientific. You can request a CoA through the product page on the Aladdin Scientific website by entering your lot number, or by contacting the customer service team directly with your order details.

References

1. Johansson Seechurn, C. C. C.; Kitching, M. O.; Colacot, T. J.; Snieckus, V. Palladium-Catalyzed Cross-Coupling: A Historical Contextual Perspective to the 2010 Nobel Prize. Angew. Chem. Int. Ed. 2012, 51, 5062–5085. doi:10.1002/anie.201107017
2. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012; pp 476–480 (nucleophilic aromatic substitution).
3. Evano, G.; Blanchard, N. (Eds.) Copper-Mediated Cross-Coupling Reactions; Wiley: Hoboken, NJ, 2013.

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