N-Methyl-4-nitroaniline
[CAS# 100-15-2]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridine compound >> Cyanopyridine
• Name: N-Methyl-4-nitroaniline
• Synonyms: 4-Nitro-N-methylaniline
• Molecular Formula: C₇H₈N₂O₂
• Molecular Weight: 152.15
• CAS Registry Number: 100-15-2
• EC Number: 202-823-2
• SMILES: CNC1=CC=C(C=C1)[N+](=O)[O-]

Properties

• Density: 1.3±0.1 g/cm³, Calc.^*
• Melting point: 149-151 ºC (Expl.)
• Index of Refraction: 1.620, Calc.^*
• Boiling Point: 290.6±23.0 ºC (760 mmHg), Calc.^*
• Flash Point: 129.5±22.6 ºC, Calc.^*
• Water solubility: <0.1 g/100 mL (19 ºC) (Expl.)

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS06;GHS08 Danger
• Hazard Statements: H301-H311-H331-H373-H412
• Precautionary Statements: P260-P261-P262-P264-P270-P271-P273-P280-P301+P316-P302+P352-P304+P340-P316-P319-P321-P330-P361+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	3	H301
Acute toxicity	Acute Tox.	3	H331
Acute toxicity	Acute Tox.	3	H311
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovory and Applicatios

N-Methyl-4-nitroaniline is a significant chemical compound with diverse applications, known for its combination of a nitro group and a methylamino group attached to an aromatic ring. This structure imparts unique electronic properties that have made it a critical substance in material sciences, organic synthesis, and analytical chemistry. Initially synthesized through nitration of N-methylaniline, the development of more efficient and selective methods has allowed its production under controlled, environmentally conscious conditions.

One of the key areas of application is in nonlinear optical materials. The electron-donating methylamino group and electron-withdrawing nitro group on the aromatic ring create a strong push-pull effect, which is critical in generating high hyperpolarizability. Crystals of N-methyl-4-nitroaniline are particularly valuable in devices requiring second harmonic generation, including laser frequency doubling and electro-optic modulation systems. These properties have driven extensive research to optimize its crystalline forms for photonic applications.

In organic synthesis, N-methyl-4-nitroaniline serves as a versatile intermediate due to its functional groups that enable reduction, substitution, and various transformations. A notable application involves the reduction of its nitro group to form N-methyl-para-phenylenediamine, which is used in synthesizing dyes, pharmaceuticals, and other specialty chemicals. The compound’s reactivity also facilitates its role in developing agrochemicals and functional materials.

The analytical utility of N-methyl-4-nitroaniline lies in its ability to form charge-transfer complexes, making it an effective reagent for detecting various compounds through spectroscopic methods. It has also been extensively studied as a model compound to understand substituent effects on aromatic systems, advancing knowledge in fundamental aromatic chemistry.

Despite its valuable properties, the handling of N-methyl-4-nitroaniline must consider its associated health and environmental risks. The compound is a known irritant, and its nitro group may present mutagenic risks. To address these concerns, safe handling practices, proper storage, and adherence to waste disposal regulations are critical in its use across industries.

Continued exploration of N-methyl-4-nitroaniline is focused on enhancing its performance in existing applications and discovering new possibilities in advanced materials. Efforts are also being made to develop sustainable production methods and mitigate its environmental footprint, ensuring its relevance in scientific and industrial contexts.