aminosalicyclic acid methyl ester to a stirred solution of 2 1 g of the product above 994 mg of pyridine and 20 ml of acetonitrile is added 1 49 g of 1 3 5 benzenetrisulfonyl chloride the mixture is stirred for a period of 60 hours then is acidified with dilute hydrochloric acid and concentrated the aqueous concentrate is extracted twice with diethyl ether the combined ether extract is washed with saturated sodium chloride dried over anhydrous sodium sulfate and evaporated to give 2 63 g of the product of the example as a pink crystalline material a solution of 500 mg of the product of example 6 and 5 ml of n sodium hydroxide is stirred at room temperature for 6 hours the solution is acidified with dilute hydrochloric acid yielding a mixture of a red oil and a cloudy aqueous solution the oil is dissolved and separated from the aqueous by the addition of diethyl ether the aqueous layer is then extracted with ether the ether solutions are combined washed with a saturated sodium chloride solution dried over anhydrous sodium sulfate evaporated and dried in vacuo to yield 335 mg of the product of the example as a white solid ______________________________________preparation of compressed tabletingredient mg tablet______________________________________active compound 0 5 500dibasic calcium phosphate n f qsstarch usp 40modified starch 10magnesium stearate usp 1.