2-Chloro-4-nitrobenzoic acid

White or yellowish acicular or powdery crystals. The melting point is 142-143 ℃ (139-141 ℃). Soluble in hot water, alcohol and hot benzene. Uses The intermediate of the drug rivanol can also be used as a disinfectant and antiseptic. Use It is used as a pharmaceutical intermediate to produce the drug rivanol. The production method is obtained by chlorination and oxidation of p-nitrotoluene. Put p-nitrotoluene into a dry reactor, heat and melt it, add iron wire and iodine sheet, at 58-62 ℃, inject equal molar amount of chlorine, wash it with hot water, neutralize it with sodium carbonate, pour it into ice water, stir it to separate crystals, filter out water, and dry it in the shade to obtain 2-chloro-4-nitrotoluene. Then add 25 times 1-2% sodium hydroxide solution into 2-chloro-4-nitrotoluene, heat it to boiling, slowly add potassium permanganate under intense stirring, keep the temperature at 100 ± 1 ℃, after adding, continue stirring, reflux for 30min, cool it, and remove manganese dioxide. The filtrate is adjusted to pH 1-2 with hydrochloric acid, the precipitation is washed with ice water, filtered, and dried at 80 ℃ to obtain the product. The chlorination operation can also be carried out in the presence of ferric chloride, and chlorine is still passed at 58-62 ℃. The total yield of chlorination and oxidation is about 70%.