The chemical properties and structure of p-bromoaniline.

Basic Information:

Alias: 4-Bromoaniline, p-Bromoaniline

CAS No: 106-40-1

Molecular Formula: C6H6BrN

Molecular Weight: 172.02

Physical State:White to light yellow to light orange solid

Melting Point:56-62°C (lit.)

Boiling Point:230-250°C

Uses:Used in the manufacturing of azo dyes and organic synthesis

Employed in the preparation of dihydroquinazoline

4-Bromoaniline is an important organic compound widely used in the fields of dyes, pharmaceuticals, and pesticides. This article will provide a detailed introduction to its chemical properties and structure.

Chemical Structure:

The molecular formula of p-bromoaniline is C6H6BrN, with a molecular weight of 172.02 g/mol. Its structure consists of a benzene ring, a bromine atom, and an amino group. The bromine atom and the amino group are located at the para position on the benzene ring (i.e., 1,4-position), and this specific structure imparts some unique chemical properties to p-bromoaniline.

The molecular structure diagram is as follows:

    Br

    |

 1-C6H4-NH2

Chemical Properties
Acidity and Basicity: The amino group (-NH2) in 4-Bromoaniline is basic and can react with acids to form salts. For instance, when it reacts with common acids like hydrochloric acid, it forms p-bromoaniline hydrochloride.
C6H4BrNH2 + HCl → C6H4BrNH3+Cl-

Reactivity of Bromine: The bromine atom has high electronegativity, which affects the electron distribution on the benzene ring, causing a shift in the electron cloud. Therefore, the reactivity of 4-Bromoaniline in certain chemical reactions is influenced by bromine. For example, in electrophilic substitution reactions, the electron-donating effect of the amino group and the electron-withdrawing effect of the bromine atom jointly influence the direction and rate of the reaction.

Redox Reactions: The amino group can be oxidized to nitroso or nitro compounds, while the bromine atom generally remains unchanged during these reactions. For instance, when p-bromoaniline is oxidized by potassium permanganate, p-bromonitrobenzene can be formed.
C6H4BrNH2 + KMnO4 → C6H4BrNO2 + MnO2 + KOH

Nucleophilic Substitution Reactions: The bromine atom, being a good leaving group, can participate in nucleophilic substitution reactions. Under strong basic conditions, the bromine atom in p-bromoaniline can be replaced by other nucleophiles, such as hydroxyl (-OH) or cyano (-CN) groups.
C6H4BrNH2 + NaOH → C6H4OHNH2 + NaBr

Due to its unique chemical structure and properties, 4-Bromoaniline finds wide applications in various fields:

1. Dye Industry: p-Bromoaniline is an important intermediate in the synthesis of various azo dyes.

2. Pharmaceuticals: Derivatives of p-bromoaniline are used as intermediates in pharmaceutical synthesis, especially in the development of antibiotics and anti-cancer drugs.

3. Pesticide Manufacturing: As an intermediate in pesticide synthesis, p-bromoaniline plays a crucial role.

4-Bromoaniline's unique chemical structure and properties, particularly its acidity/basicity, bromine reactivity, and behavior in redox and nucleophilic substitution reactions, make it an important chemical in various industrial fields.