The crude product N-methyl-N-(1-naphthylmethyl)formamide prepared according to step (a) was suspended in 300 mL of 20% aqueous sodium hydroxide solution and the reaction was heated at 60-70°C for 7 hours. Upon completion of the reaction, the mixture was cooled to 25 °C and subsequently extracted with toluene (2 x 200 mL). The toluene extracts were combined and back-extracted with 3N hydrochloric acid (2 x 300 mL). The aqueous phase was decolorized with activated carbon and the pH was adjusted with 20% aqueous sodium hydroxide to 10.0. The released free base was extracted with toluene, and the toluene layers were combined and distilled to remove the solvent to give 86 g of crude product. Finally, 82 g (85% yield) of pure N-methyl-1-naphthalenemethylamine was obtained by high vacuum distillation purification.
