5-Nitroisophthalic acid → 2-Nitro-1,3-benzenedicarbonyl dichloride

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Reaction Steps

A mixture of 100 g of 5-nitroisophthaloyl dichloride (prepared by taking a mixture of 60.0 g of 5-nitroisophthalic acid, 300 ml of thionyl chloride and one ml of dimethylformamide, stirring at room temperature for 30 minutes followed by refluxing for one hour; allowing the solution to stand 24 hours, followed by evaporation to a small volume in vacuo re-evaporating with toluene and then diluting the resulting liquid with 250 ml of hexane, followed by stirring and cooling until the resulting oil is solidified; and grinding the product to a powder, and recrystallizing twice from carbon tetrachloride to afford 47.4 g of nitroisophthaloyl chloride) 100 g of 2-methoxyethanol (dried over molecular sieves) and 400 ml of acetonitrile (dried over molecular sieves) is heated to boiling on a steam bath. Heating is continued for 15 minutes, then the mixture is cooled to room temperature and is poured into 2 liters of cold water with vigorous stirring. The precipitate formed (129 g) is collected by filtration, air dried and set aside. The above filtrate is extracted with benzene. The benzene extract is washed with water, dilute sodium dicarbonate and water and is dried over anhydrous sodium sulfate. The solvent is evaporated to give a mixture of crystals and oily liquid. This material is combined with the precipitate set aside above and dissolved in 580 ml of hot ethyl alcohol. The resultant solution is neutralized with 5.0 ml of 5N sodium hydroxide and is slowly diluted with 450 ml of water. The solution is allowed to crystallize at room temperature then is placed in a chill room for 16 hours. The product is collected by filtration, then is recrystallized and filtered as above from 450 ml of ethyl alcohol and 350 ml of water to give 92.1 g of 5-nitroisophthalic acid bis(2-methoxyethyl)ester as colorless needles.

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