Hydrochloric Acid → N,N'-Diphenylterephthaldiamide

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Reaction Steps

N,N'-diphenylterephthalamide (Structure I) is synthesized from aniline and terephthaloyl chloride using acetone as a reaction media and an aqueous solution of NAOH to neutralize the HCl generated. Terephthaloyl chloride (87.2 grams, 0.43 moles) is first added to a stirred, 2-liter reaction flask containing one liter of acetone. After the terephthaloyl chloride has dissolved, aniline (80.0 grams, 0.86 moles) is added dropwise using an addition funnel over a 30 minute period. During the course of this addition, a white precipitate is formed. A 200 ml aqueous solution of NaOH (34.3 grams, 0.86 moles) is then added, also using an addition funnel, over a 30 minute period. The reaction temperature during both the aniline and NAOH addition is maintained below 35° C. by blowing air onto the outside of the reaction flask. After the NAOH addition, the reaction mixture is stirred for three hours and then vacuum filtered (filtrate pH=7). The filter cake obtained is washed with 400 ml of acetone and then added to one liter of deionized water, stirred for 15 minutes and filtered. This filter cake is washed with 500 ml of acetone and then dried in a 105° C. vacuum oven to a constant weight. This final product (114.4 grams, yield=84.2%) exhibited a sharp melting endotherm by differential scanning calorimetry (DSC) at 346° C. Also Fourier transform infrared (FTIR) analysis showed the following absorbances which are indicative of the structure for the final product: 3329 cm-1 (N-H stretch), 1528 cm-1 (Amide II band) and 1650 cm--1 (Amide I band). ##STR9##

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