First, dimethylamino-2-phenoxyethanewas made by reacting chloro-2-
phenoxyethane with dimethylamine. Benzyl chloride (10 grams) was then
added to a solution of 1-dimethylamino-2-phenoxyethane (12.3 grams) in
acetone (35 ml). The mixture warmed spontaneously and N-benzyl-N,Ndimethyl-N-2-phenoxyethylammonium chloride slowly crystallized. After 24
hours, this solid was filtered off, washed with fresh acetone and dried
immediately in vacuo, MP 135°-136°C.
2-Hydroxy-3-naphthoic acid (1.88 grams) was dissolved in hot aqueous
sodium hydroxide (0.5N; 20 ml) and the resulting solution was slowly added
to a solution of N-benzyl-N,N-dimethyl-N-2-phenoxyethylammonium chloride
(2.9 grams) in water (5 ml). A gum separated at first but it solidified on
scratching. After the addition was complete, the mixture was allowed to stand
at room temperature for 2 hours and then filtered. The residue was washed
with water and dried in vacuo to give N-benzyl-N,N-dimethyl-N-2-
phenoxyethylammonium 2-hydroxy-3-naphthoate, MP 170°-171°C.
