The preparation of 2-chloro-4-nitroaniline from aniline and chlorine gas involves a two-step process: nitration followed by chlorination. Here are the optimum conditions for each step:1. Nitration of aniline to form 4-nitroaniline:- Temperature: 0-5C ice bath - Reaction time: 30-60 minutes- Reagents: Concentrated sulfuric acid H2SO4 and concentrated nitric acid HNO3 in a 1:1 ratio- Procedure: Dissolve aniline in concentrated H2SO4, then slowly add the mixture of H2SO4 and HNO3 to the aniline solution while maintaining the temperature at 0-5C. After the reaction time, pour the mixture into crushed ice and filter the precipitate.2. Chlorination of 4-nitroaniline to form 2-chloro-4-nitroaniline:- Temperature: 40-60C- Pressure: Atmospheric pressure- Reaction time: 2-4 hours- Reagents: Chlorine gas Cl2 and a suitable solvent e.g., acetic acid - Procedure: Dissolve 4-nitroaniline in the solvent and then bubble chlorine gas through the solution while maintaining the temperature at 40-60C. After the reaction time, cool the mixture, filter the precipitate, and wash it with cold solvent to obtain the final product.These conditions should provide a high yield and purity of 2-chloro-4-nitroaniline. However, it is important to note that the reaction conditions may need to be adjusted depending on the specific equipment and reagents used. Always perform a small-scale test reaction to optimize the conditions for your specific setup.