Bromination of Aniline

Direct Bromination (Uncontrolled):

$$\begin{aligned}\text{C}_6\text{H}_5\text{NH}_2 + 3\text{Br}_2 \xrightarrow{\text{H}_2\text{O}} 2,4,6\text{-Tribromoaniline}\downarrow \text{ (White Precipitate)} + 3\text{HBr}\end{aligned}$$

Controlled Monobromination (via Protection):

$$\begin{aligned}\text{C}_6\text{H}_5\text{NH}_2 \xrightarrow{(\text{CH}_3\text{CO})_2\text{O} / \text{Pyridine}} \text{C}_6\text{H}_5\text{NHCOCH}_3 \xrightarrow{\text{Br}_2 / \text{CH}_3\text{COOH}} p\text{-Bromoacetanilide} \xrightarrow{\text{H}^+ / \text{H}_2\text{O}} p\text{-Bromoaniline}\end{aligned}$$