Aniline → N-benzene sulfonyl phenyl cyanamide

To a 3 liter 3-necked flask equipped with a stirrer, addition funnel, thermometer, and drying tube was charged 93.1g (1.0 mole) of aniline, 111g (1.1 moles) of triethylene diamine and 250 ml. of tetrahydrofuran. To this reaction mixture was added dropwise a solution of 176.6g (1 mole) of benzenesulfonyl chloride in 300 ml. of tetrahydrofuran. The reaction mixture was stirred at room temperature for 2.5 hours and was then filtered. To the filtrate was added 111g of triethylene diamine and this solution was added dropwise to a solution of 87g (1.41 moles) of cyanogen chloride in 100 ml. of THF which was maintained at -5°C. with cooling, After this addition was complete the stirred reaction mixture was allowed to return to room temperature over a 161/2 hour period. The reaction mixture was filtered and the filament was added to water to precipitate the product. The product was recrystallized from aqueous methanol to yield 218g (84.7%) of N-benzene sulfonyl phenyl cyanamide, m.p. 65°-66°C.