Chemical Identity and Physicochemical Properties

2-Chloro-4-nitro-N-methylaniline is a substituted aromatic amine bearing three key functional groups on the benzene ring: a secondary N-methylamino group at position 1, a chloro substituent at position 2, and a nitro group at position 4. Its molecular formula is C₇H₇ClN₂O₂, giving a calculated molecular weight of approximately 186.59 g/mol.

The electron-withdrawing nitro group at the para position and the ortho chloro group exert a combined inductive and mesomeric effect that significantly reduces the nucleophilicity of the nitrogen lone pair compared with unsubstituted N-methylaniline. This electronic deactivation affects reactivity in nucleophilic aromatic substitution (SNAr) and electrophilic reactions.

The compound is expected to be a low-melting solid at ambient conditions. Specific melting point, boiling point, solubility, and spectral data should be verified against the product Certificate of Analysis (CoA) available from Aladdin Scientific for lot C153772. Solubility in common organic solvents such as dimethyl sulfoxide (DMSO), dichloromethane (DCM), and ethyl acetate is anticipated based on its molecular structure, but experimental solubility data should be confirmed.

Synthesis Applications and Reactivity

2-Chloro-4-nitro-N-methylaniline serves as a versatile intermediate in several classes of organic synthesis:

• Dye and pigment chemistry: Halogenated nitroanilines are classical precursors in the synthesis of azo dyes and disperse dyes used in textile and photographic industries. The chloro substituent at the ortho position can participate in coupling or displacement reactions.
• Pharmaceutical intermediates: The compound's combination of an N-methylamino group, an aryl chloride, and a nitro group makes it a valuable scaffold for constructing heterocyclic frameworks via cyclization, or for reduction of the nitro group to yield a diaminochlorobenzene derivative for further functionalization.
• Agrochemical research: Halogenated anilines are frequently employed as building blocks in the synthesis of herbicides, fungicides, and insecticides.
• SNAr reactions: The activated aryl chloride (activated by the ortho-chloro and para-nitro combination) can undergo nucleophilic aromatic substitution with amines, thiols, or alkoxides under appropriate conditions.

Researchers should optimize reaction conditions (solvent, base, temperature) empirically, as substrate-specific reactivity can vary. The nitro group can be selectively reduced to an amine using catalytic hydrogenation (Pd/C, H₂) or chemical reductants (Fe/AcOH, SnCl₂), providing access to the corresponding 1,3-diamine intermediate.

Safe Handling, Storage, and Waste Disposal

Hazard classification: As a halogenated aromatic nitro compound, 2-Chloro-4-nitro-N-methylaniline should be treated as a potentially toxic and irritating substance. Consult the Safety Data Sheet (SDS) for the specific lot before use. Nitroaromatic amines as a class are associated with methemoglobin-forming potential and possible skin sensitization.

Personal Protective Equipment (PPE): Use nitrile gloves, safety goggles, and a lab coat as a minimum. When handling as a powder, work in a fume hood or use a dust mask rated for fine chemical particulates (minimum P2/N95 equivalent) to avoid inhalation.

Storage: Store in a cool, dry, well-ventilated location away from oxidizing agents, strong acids, and reducing agents. Keep container tightly sealed. Recommended storage temperature is typically 2–8 °C or room temperature as specified on the product label — verify with the Aladdin CoA for C153772. Protect from light to prevent photodegradation of the nitro group.

Waste disposal: Dispose of as halogenated organic waste in accordance with institutional and local environmental regulations. Do not pour down the drain. Label all waste containers appropriately.

Note: Specific GHS hazard codes and pictograms should be confirmed from the official Aladdin SDS for C153772 prior to use.

Analytical Characterization and Quality Verification

Prior to use in sensitive synthetic steps, researchers are advised to verify the identity and purity of 2-Chloro-4-nitro-N-methylaniline using appropriate analytical techniques:

• Thin-Layer Chromatography (TLC): A rapid and inexpensive first-line check. Use silica gel plates with a suitable eluent (e.g., hexane/ethyl acetate mixtures). The nitro group enables visualization under UV light at 254 nm.
• HPLC: Reverse-phase HPLC (C18 column, UV detection at 254 nm or 300 nm) provides quantitative purity assessment. The CoA from Aladdin specifies the guaranteed purity level for C153772.
• ¹H NMR Spectroscopy: Key diagnostic signals include the N-CH₃ singlet (expected ~δ 2.9–3.0 ppm), the N-H signal (broad, if present), and aromatic proton signals characteristic of a 1,2,4-trisubstituted benzene pattern. Confirm the number and multiplicity of aromatic protons.
• Mass Spectrometry (MS): Confirm the molecular ion at m/z 186/188 (isotope pattern consistent with one chlorine atom).
• Melting Point: Compare against literature or CoA specification as an identity and purity check.

For GMP or regulatory applications, request the full Certificate of Analysis and, where required, an independent third-party analytical report.