To a vigorously stirred mixture of (3-amino-4-benzyl-5-sulfamylbenzyl)dimethylamine dihydrochloride hemihydrate (4.0 g; prepared as described in Example 209), 2 N sodium hydroxide (60 ml) and methylene chloride (40 ml) a solution of n-butyryl chloride (1.1 g) in methylene chloride (12 ml) is dropwise added during 30 minutes keeping the temperature at 0°-5° C. by external cooling. After additional stirring at 22°-25° C. for 2 hours, the organic layer is separated, washed with water and dried in the presence of magnesium sulphate. The methylene chloride is then removed in vacuo to yield crude (4-benzyl-3-n-butyrylamido-5-sulfamylbenzyl)dimethylamine as an oil. The crude amine is dissolved in dry 1,2-dimethoxyethane (50 ml) and the resulting solution is dropwise added at 100° C. during 45 minutes to a stirred mixture of lithium aluminium hydride (2.0 g) and 1,2-dimethoxyethane (40 ml). After additional refluxing and stirring for 16 hours, the mixture is cooled, and ethyl acetate (4 ml) followed by water (8 ml) are very cautiously added. The mixture is stirred for a further 30 minutes and is then heated on a steam-bath and filtered hot. The filtercake is carefully washed with hot 1,2-dimethoxyethane (3 portions of 25 ml), whereafter the combined filtrates are evaporated in vacuo to yield crude (4-benzyl-3-n-butylamino-5-sulfamylbenzyl)dimethylamine. After recrystallization from ethanol it is obtained with a melting point of 111°-113° C. The material (IR, analysis) is identical with the material prepared as in Example 172.
