the catalyst was removed by filtration the filtrate was treated with charcoal s 51 filtered again and the solvent was removed on a rotary evaporator the last traces of the solvent were removed on vacuum pump and the residue which was a thick syrup with a greenish tinge was identified as the required diamino derivative 6 2 g a solution of 2 nitrobenzenesulfonyl chloride 40 g in methylene chloride 150 ml was added slowly to a stirred solution of methylene chloride 150 ml containing ethylene diamine 4 9 g and triethylamine 18 2 g at 0 u00b0 c the reaction was continued at room temperature for 24 hours and filtered to remove the triethylamine hydrochloride on addition of water 200 ml to the organic solution a white precipitate was obtained after the separation of the layers the material that was insoluble in methylene chloride was obtained by filtration it was then recrystallized from methanol to give the product 30 g as colorless crystals m p 115 u00b0 c dec tlc solvent system dcm rf 0 2 a mixture of n n u2032 bis 2 nitrosulfonyl 1 2 diaminoethane 5 g example 6 potassium carbonate 4 8 g and n 6 bromohexyl phthalimide 7 93 g in 35 ml of dimethylformamide were stirred and heated to 80 u00b0 c for 4 hours after allowing the reaction mixture to come to room temperature the contents were poured into water 100 ml and the solid that was obtained was filtered washed with methanol and dried in a oven for.