A solution of 5.55 g (0.030 mole) of 2-(phenylsulfonyl)ethanamine and 5.35 g (0.033 mole) of 1,1'-carbonyldiimidazole in 400 ml of tetrahydrofuran was stirred at room temperature for 1 hr. A solution of 4.62 g (0.032 mole) of N,N,N'-triethylethylenediamine in 50 ml of tetrahydrofuran was added, and the mixture was refluxed for 16 hr. The solvent was removed in vacuo, and the residue was partitioned between a mixture of 300 ml of methylene chloride and 500 ml of ether and water. The organic phase was dried over magnesium sulfate, and the solvent was removed in vacuo to give an oil. A solution of the oil in methanol was treated with an equivalent of citric acid and ether was added. A white precipitate formed to give 8.54 g (52.0%) of white crystalline solid, m.p. 105°-107° C.
