The preparation of 2-chloro-4-nitroaniline from aniline and chlorine gas involves a two-step process. First, aniline is nitrated to form 4-nitroaniline, and then it is chlorinated to form 2-chloro-4-nitroaniline.1. Nitration of aniline:The nitration of aniline is carried out using a mixture of concentrated sulfuric acid and nitric acid. The optimum reaction conditions for this step are:- Temperature: 0-5C ice bath - Time: 30-60 minutesIt's essential to maintain a low temperature during this step to avoid the formation of undesired by-products.2. Chlorination of 4-nitroaniline:The chlorination of 4-nitroaniline is performed using chlorine gas in the presence of a catalyst, such as cupric chloride CuCl2 . The optimum reaction conditions for this step are:- Temperature: 40-60C- Time: 2-4 hoursThese conditions should provide a high yield and purity of 2-chloro-4-nitroaniline. However, it's important to note that reaction conditions may vary depending on the specific setup and reagents used. Always consult the literature and perform small-scale experiments to optimize the conditions for your specific situation.