General procedure for the synthesis of 3-chloro-1-(N,N-dimethyl)propylamine from N,N-dimethylaminopropyl chloride hydrochloride: flake solid NaOH (42.1 g, 1052.5 mmol, 1.0 eq.) was dissolved in 142.1 g of water, a process which is exothermic, and an aqueous NaOH solution was obtained and then cooled down to 30 °C. In a 500 mL two-neck flask, HCl (104 g, 658 mmol, 1.0 eq.) and the above aqueous NaOH solution were added, the temperature was raised to 45 °C and the reaction was started with continuous stirring for 2 hours. After completion of the reaction, the reaction solution was cooled to room temperature (30 °C). The organic layer was separated and collected to give 74.93 g of wet 3-chloro-1-(N,N-dimethyl)propylamine (CPA). The water content of the product was determined to be 2.755% and the yield was 91.07% (as anhydrous CPA).
