85 g of levorotatory 1-allyl-2-aminomethyl-pyrrolidine, 610 cm3 of chloroform, and gradually, 178 g of 7-methylsulfamoyl-1,4-benzodioxane-5-carbonyl chloride at a temperature of from 5°-10° C. were introduced into a balloon flask provided with an agitator and a thermometer. After agitation of the mixture 1.2 liters of water were added and then chloroform was distilled. The remaining solution was filtered and then the base was precipitated with 70 cm3 of 20% ammonia. The crystals formed were dried off and washed with water. After recrystallization from ethyl acetate, 117 g of levorotatory-N-(1-allyl-2-pyrrolidylmethyl)-7-methylsulfamoyl-1,4-benzodioxane-5-carboxamide was produced (M.P.: 101°-102° C.; yield: 49%).
