A solution of 3-chloro-N-[(1R)-1-(naphthalen-1-yl)ethyl]prop-2-en-1-amine (Example 1; 50 g), iron acetylacetonate (3.6 g) and N-methyl-2-pyrrolidone (1.0 g) in tetrahydrofuran (200 mL) at 0 to −5° C. was added to a solution of 3-(trifluoromethyl)phenyl magnesium bromide (Example 3) in tetrahydrofuran (150 mL) at −25° C. to −30° C. under inert atmosphere. The reaction mixture was stirred at 0 to 5° C. for 15 to 20 minutes. After the completion of the reaction, de-ionized water (75 mL) was added at 0 to 10° C. Toluene (250 mL) was added to the reaction mixture and the pH of mixture was adjusted to 0 to 1 using hydrochloric acid (6 Normal; 250 mL) at 10° C. to 35° C. and stirred at the same temperature for about 15 minutes. Layers were separated, and the organic layer was washed with de-ionized water (2×250 mL) and concentrated under vacuum at 55° C. to 60° C. Isopropyl alcohol (125 mL) was added to the residue obtained and heated to 40° C. to 45° C. to get a clear solution. The solution was cooled to 20° C. to 30° C. and stirred for about 2 hours to give solid. The solid was filtered, washed with isopropyl alcohol (2×50 mL) and dried under vacuum at 45° C. to 50° C. to give N-[(1R)-1-(naphthalen-1-yl)ethyl]-3-[3-(trifluoromethyl)phenyl]prop-2-en-1-amine hydrochloride.
