The most efficient method of preparing 2-chloro-4-nitroaniline from aniline and chlorine gas involves a two-step process: nitration followed by chlorination.Step 1: Nitration of AnilineFirst, protect the amino group of aniline by acetylating it with acetic anhydride to form acetanilide. This step is crucial because the amino group is highly reactive and can interfere with the nitration process.Next, nitrate the acetanilide by adding a mixture of concentrated sulfuric acid and concentrated nitric acid. This will form 4-nitroacetanilide.Step 2: ChlorinationIn this step, 4-nitroacetanilide is reacted with chlorine gas in the presence of a catalyst, such as ferric chloride FeCl3 , to form 2-chloro-4-nitroacetanilide.Finally, hydrolyze the 2-chloro-4-nitroacetanilide using aqueous sodium hydroxide NaOH to remove the acetyl protecting group and obtain 2-chloro-4-nitroaniline.Purity Determination:The purity of the final product can be determined using various analytical techniques, such as:1. Thin Layer Chromatography TLC : This method can be used to check the purity and monitor the progress of the reaction.2. Melting Point Determination: A pure compound has a sharp melting point, while impurities usually lower and broaden the melting point range.3. Infrared Spectroscopy IR : This technique can be used to confirm the presence of specific functional groups in the final product.4. Nuclear Magnetic Resonance NMR Spectroscopy: NMR can provide detailed information about the molecular structure and purity of the compound.Potential Hazards:1. Aniline is toxic and can be absorbed through the skin. It is essential to wear appropriate personal protective equipment PPE such as gloves, lab coat, and goggles.2. Concentrated acids sulfuric and nitric acids are highly corrosive and can cause severe burns. Handle them with care and use a fume hood to avoid inhaling their vapors.3. Chlorine gas is highly toxic and can cause respiratory problems. It should be handled in a well-ventilated area or a fume hood, and proper PPE should be worn.4. Ferric chloride is a corrosive solid and can cause skin and eye irritation. Handle it with care and wear appropriate PPE.Always follow proper laboratory safety procedures and dispose of waste materials according to local regulations.