1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene: Handling & Use Protocol

1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene is a polyfunctionally substituted aromatic building block widely employed as an electrophilic intermediate in nucleophilic aromatic substitution (SNAr) reactions and as a key precursor in the synthesis of pharmaceutically relevant heterocyclic and carbocyclic targets.

Chemical Name

1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene

SKU / Catalog Number

C186861

Molecular Formula

C7H5ClFNO3

Molecular Weight

209.57 g/mol

Key Functional Groups

Chloro, fluoro, methoxy, nitro substituents on benzene ring

Primary Application

SNAr substrate; pharmaceutical and agrochemical intermediate

Storage Recommendation

Cool, dry, well-ventilated area; away from heat and incompatible materials

Scope and Reagent Overview

This protocol covers the safe receipt, storage, preparation of stock solutions, and use of 1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene (Aladdin SKU C186861) in laboratory-scale synthetic chemistry. The compound is a multisubstituted benzene derivative bearing electron-withdrawing nitro and halogen groups alongside an electron-donating methoxy group. This electronic asymmetry makes it a versatile electrophile for nucleophilic aromatic substitution (SNAr), transition-metal-catalyzed cross-coupling, and nitro-group reduction sequences commonly encountered in medicinal chemistry and materials science research.

The presence of the nitro group ortho/para-activating the ring toward nucleophilic attack at the chloro and fluoro positions, combined with the methoxy group, allows selective displacement under mild to moderate conditions. Researchers should consult the applicable Safety Data Sheet (SDS) before use and follow all institutional chemical safety protocols.

Safety, Storage, and Handling

Personal Protective Equipment (PPE): Wear chemical-splash goggles, a laboratory coat, and nitrile gloves when handling this compound. Work in a well-ventilated fume hood to avoid inhalation of dust or vapors. Nitroaromatic compounds are generally regarded as potential irritants and should be treated as hazardous until full toxicological data are confirmed via the SDS.

Storage: Store the reagent in a tightly sealed container in a cool (below 25 °C), dry, and well-ventilated location, away from heat sources, open flames, strong oxidizers, and strong bases. Keep the container closed when not in use to prevent moisture uptake and degradation.

Waste Disposal: Dispose of waste solutions and contaminated materials in accordance with local, national, and institutional regulations for halogenated and nitroaromatic organic waste. Do not pour down the drain.

First Aid: In case of skin contact, wash immediately with soap and water for at least 15 minutes. For eye contact, flush with copious amounts of water and seek medical attention. If inhaled, move to fresh air and consult a physician.

Stock Solution Preparation and Solubility

Recommended Solvents: 1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene is expected to dissolve readily in common polar aprotic organic solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), acetonitrile, and dichloromethane (DCM), as well as in ethyl acetate and tetrahydrofuran (THF). Aqueous solubility is anticipated to be low due to the lipophilic halogenated aromatic core.

Procedure for Stock Solution:

1. Weigh the required amount of reagent into a pre-dried, tared glass vial inside the fume hood using an analytical balance.
2. Add the chosen anhydrous solvent in small portions and swirl gently or use an ultrasonic bath until complete dissolution is achieved.
3. Prepare stock solutions at a concentration appropriate for downstream reactions (e.g., 0.1–1.0 M for synthetic applications).
4. Label the vial with compound name, SKU (C186861), concentration, solvent, date of preparation, and preparer's initials.
5. Store stock solutions at 2–8 °C under inert atmosphere (N2 or Ar) if prolonged storage is required; use within a reasonable period to avoid decomposition.

Note: Actual solubility data for this specific compound should be experimentally verified. The recommendations above are based on general physicochemical principles for structurally similar halogenated nitrobenzene derivatives.

Representative Synthetic Applications

1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene serves as a reactive electrophilic partner in several classes of organic reactions:

1. Nucleophilic Aromatic Substitution (SNAr): The electron-withdrawing nitro group at the 4-position (relative to fluorine) strongly activates the C–F bond toward displacement by nitrogen-, oxygen-, and sulfur-centered nucleophiles under mild base conditions (e.g., K2CO3 in DMF, 60–100 °C). The C–Cl bond may also be selectively displaced under more forcing conditions or with harder nucleophiles, enabling sequential functionalization.

2. Transition-Metal-Catalyzed Coupling: The aryl chloride functionality is amenable to palladium-catalyzed cross-coupling reactions (Suzuki-Miyaura, Buchwald-Hartwig amination) using appropriate ligand systems. The methoxy and nitro substituents provide handles for subsequent functional-group interconversion.

3. Nitro Group Reduction: Chemoselective reduction of the nitro group (e.g., using Fe/AcOH, Zn/NH4Cl, catalytic hydrogenation with Pd/C under H2, or transfer hydrogenation conditions) yields the corresponding aniline derivative, a valuable scaffold for further elaboration into amides, ureas, or heterocycles.

Researchers should optimize reaction conditions empirically. Yields and selectivities will depend on nucleophile identity, base, solvent, temperature, and reaction time.

Quality Control and Analytical Characterization

Upon receipt, verify the identity and purity of 1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene (C186861) using one or more of the following analytical techniques before use in sensitive applications:

• TLC: Run on silica gel using an appropriate solvent system (e.g., hexane/ethyl acetate mixtures); visualize under UV light (254 nm) and/or KMnO4 stain. A single spot confirms gross purity.
• 1H NMR and 19F NMR: The aromatic proton pattern and the characteristic 19F resonance provide definitive structural confirmation. The methoxy singlet (~3.9 ppm, 3H) and two aromatic protons (expected as singlets due to the 1,2,4,5-tetrasubstituted pattern) are diagnostic signals.
• GC or HPLC: Quantitative purity assessment by gas chromatography or reversed-phase HPLC using a C18 column with UV detection at 254 nm.
• Mass Spectrometry: Confirm molecular ion consistent with MW 209.57 (C7H5ClFNO3); isotope pattern confirms chlorine presence.

The Certificate of Analysis (CoA) supplied with each lot from Aladdin Scientific provides the purity specification and analytical data for that specific batch. Always cross-reference with the CoA upon receipt.

Frequently asked questions

Which bond is more reactive toward SNAr in 1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene, C–F or C–Cl?

In nucleophilic aromatic substitution, fluorine is generally the preferred leaving group when the ring is activated by electron-withdrawing groups, because the high electronegativity of fluorine stabilizes the Meisenheimer complex intermediate better than chlorine despite the weaker C–F bond thermodynamically as a leaving group in aliphatic systems. Therefore, the C–F bond at position 5 is typically more reactive toward SNAr under mild conditions. The C–Cl bond requires more forcing conditions or can be engaged via transition-metal catalysis.

What solvents are recommended for dissolving C186861 for synthetic use?

Polar aprotic solvents such as DMF, DMSO, acetonitrile, and THF are recommended for dissolving 1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene. Dichloromethane and ethyl acetate are also suitable for workup and chromatographic purposes. Aqueous solubility is expected to be low. Always use anhydrous solvents for moisture-sensitive reactions and verify solubility experimentally for your specific application.

How should 1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene be stored to maintain stability?

Store the compound in a tightly sealed container at room temperature or below (ideally below 25 °C), in a cool, dry, and well-ventilated area away from heat, light, and incompatible substances such as strong oxidizers and strong bases. For long-term storage of dissolved stock solutions, keep at 2–8 °C under an inert atmosphere. Always consult the Aladdin Scientific Certificate of Analysis and SDS for lot-specific storage recommendations.

Can the nitro group in this compound be selectively reduced without affecting the halogen substituents?

Yes, chemoselective nitro group reduction is generally achievable using mild conditions such as iron powder in acetic acid (Fe/AcOH), zinc in ammonium chloride (Zn/NH4Cl), or catalytic transfer hydrogenation (e.g., ammonium formate with Pd/C). These methods typically leave aryl chloride and aryl fluoride bonds intact. However, classical catalytic hydrogenation (H2/Pd/C at elevated pressure) may cause partial or complete dehalogenation and should be used with caution. Empirical optimization is recommended for each specific substrate and reaction scale.

References

1. March, J.; Smith, M. B. March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 7th ed.; Wiley: Hoboken, NJ, 2013. (General SNAr reactivity of activated aryl halides.)
2. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (Nucleophilic aromatic substitution mechanism and leaving group reactivity.)
3. Aladdin Scientific. Certificate of Analysis, 1-Chloro-5-fluoro-2-methoxy-4-nitrobenzene, SKU C186861. (Lot-specific purity and analytical data; consult current CoA at aladdinsci.com.)

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.