What is the Difference Between Aniline and N-Methylaniline

The key difference between aniline and N-methylaniline is that aniline is a primary aromatic amine, whereas N-methylaniline is a secondary amine.

Aniline and N-methylaniline are two important organic compounds having many industrial and chemical applications. They are related to each other in terms of the aniline basic structure.

CONTENTS

1. Overview and Key Difference
2. What is Aniline  
3. What is N-Methylaniline
4. Aniline vs N-Methylaniline in Tabular Form
5. Summary – Aniline vs N-Methylaniline 

What is Aniline?

Aniline is an aromatic organic compound having the chemical formula C₆H₅NH₂. It has a benzene ring (a phenyl group) attached to an amine group (-NH2). It is the simplest aromatic amine because there are no components other than the amine group and the aromatic ring. This compound is also slightly pyramidalized and is flatter than an aliphatic amine. Its molar mass is 93.13 g/mol. Furthermore, its melting point is −6.3 °C, while the boiling point is 184.13 °C. It has the odour of rotten fish.

Industrially, we can produce this compound via two steps. The first step is the nitration of benzene with a concentrated mixture of nitric acid and sulfuric acid (at 50 to 60 °C). This gives nitrobenzene. Then we can hydrogenate nitrobenzene into aniline in the presence of a metal catalyst. Moreover, this compound is mainly used in the manufacture of polyurethane precursors. Apart from that, we can use this compound in the production of dyes, drugs, explosive materials, plastics, photographic, and rubbery chemicals.

What is N-Methylaniline?

N-methylaniline is an organic compound having the chemical formula C₇H₉N. it is also known as methylaniline and monomethylaniline. The molar mass of this compound is 107.15 g/mol. It appears as a colorless to brown liquid with a high viscosity. Moreover, this liquid is insoluble in water and is denser than water. The contact of N-methylaniline with the skin can cause irritation of the skin, eyes, and mucous membrane. Therefore, it is toxic when ingested as well.

The odor of n-methylaniline is weak and ammonia-like. It has a density of about 0.99 g/mL. The melting point of this compound is -57 degrees Celsius, and the boiling point can range from 194-196 degrees Celsius.

The major use of n-methylaniline is as a fuel additive. It is a principal ingredient in NMA or monomethylaniline, which is a non-traditional antiknock agent that is increasingly applied in petroleum refineries and fuel distributors. This can increase the octane number of gasoline petrol.

What is the Difference Between Aniline and N-Methylaniline?

Aniline and n-methylaniline are two important organic compounds having many industrial and chemical applications. These two are related to each other in terms of the aniline basic structure. The key difference between aniline and N-methylaniline is that aniline is a primary aromatic amine, whereas N-methylaniline is a secondary amine. This is because the aniline compound has a chemical structure where a benzene ring is substituted with one -NH2 group, while n-methylaniline has a -NHNH2. Moreover, in the carbylamine test, aniline gives a positive result, whereas n-methylaniline gives a negative result.

Below is a summary of the difference between aniline and N-methylaniline in tabular form for side-by-side comparison.

Summary – Aniline vs N-Methylaniline

Aniline is an aromatic organic compound having the chemical formula C₆H₅NH_2, while N-methylaniline is an organic compound having the chemical formula C₇H N. The key difference between aniline and N-methylaniline is that aniline is a primary aromatic amine, whereas N-methylaniline is a secondary amine. This is because the aniline has a benzene ring with one -NH2 group, while n-methylaniline has a -NHNH2 group attached to a benzene ring.

Reference:

1. “N-Methylaniline.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine.

Image Courtesy:

1. “Aniline” By Chem Sim 2001 – Own work (Public Domain) via Commons Wikimedia
2. “N-Methylaniline” By Ljgua124 – Own work (CC BY-SA 3.0) via Commons Wikimedia