A mixture of (3-amino-4-benzyl-5-sulfamylbenzyl)dimethylamine dihydrochloride hemihydrate (4.0 g; dried in vacuo at 78° C. for 16 hours; prepared as described in Example 209), n-butyl iodide (1.9 g), sodium hydrogen carbonate (5.0 g) and hexamethylphosphoric triamide (20 ml) is stirred at 22°-25° C. for 24 hours, and is then diluted with water (200 ml) to precipitate crude (4-benzyl-3-n-butylamino-5-sulfamylbenzyl)dimethylamine. After filtration and 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.
