Bis(2-chloroethyl)amine hydrochloride (25.2 g, Tokyo Chemical Industry CO., LTD.) was suspended in dichloromethane (280 mL) and the suspension was cooled to 0 °C. Pyridine (24 mL) and p-toluenesulfonyl chloride (28.3 g) were added sequentially under stirring, followed by stirring the reaction mixture for 4 hours at room temperature. Upon completion of the reaction, saturated aqueous sodium bicarbonate solution was added to the mixture for neutralization, and then the organic phase was extracted with dichloromethane. The organic layer was washed sequentially with 1N aqueous hydrochloric acid and deionized water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the solvent. The crude product obtained was purified by silica gel column chromatography with the eluent being hexane-ethyl acetate in different ratios (15:1 to 5:1) to afford N,N-bis(2-chloroethyl)-4-methylbenzenesulfonamide (30.0 g, 71% yield). The structure of the product was confirmed by 1H-NMR (300 MHz, DMSO-d6): δ 2.41 (3H, s, CH3), 3.45 (4H, t, J = 6.9 Hz, CH2Cl), 3.72 (4H, t, J = 6.9 Hz, CH2N), 7.44 (2H, d, J = 8.2 Hz, ArH), 7.75 (2H, d, J = 8.2 Hz, ArH).
