DETERMINATION OF SULFONE-ANILIDES OF UNSATURATED CARBOXYLIC-ACIDS BY COUPLING POTENTIOMETRIC TITRATION WITH OTHER METHODS

p-Sulfone-anilide of maleic acid obtained from sulfanilic acid and mal eic anhydride has been determined by potentiometric titration with NaO H solution. Taking into account the synthesis conditions, unreacted co mpounds may accompany the main product. For a complete characterizatio n of the crude p-sulfone-anilide, other methods have been used. Thus, the sodium determination by flame photometry and the gravimetric sulfu r estimation have been performed. Also, the sodium content is indirect ly evaluated by titration with NaOH solution after ion exchange on Dow ex 50 in H form.