Hydrochloric Acid → N-propyl-6-methoxy-1,2,3,4-tetrahydro-2-naphthylamine

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Reaction Conditions

Reaction Steps

Propylamine hydrochloride (169 g, 1.8 mol) was dissolved in methanol (370 mL) and 6-methoxy-2-tetralone (50 g, 0.28 mol) was added. Thereafter, sodium cyanoborohydride (44.2 g, 0.7 mol) was added portionwise with cooling. During the latter addition, the temperature of the reaction mixture was kept at 20° C. to minimize foaming. The resulting suspension was stirred at room temperature (25° C.) for 18 hr. Excess hydrochloric acid (1:1) was added and the white suspension was cooled in ice. The solid was collected on a filter and washed with methanol (3×200 mL) to give 92 g of crude product. The crude product was treated with 10% (w/v) sodium hydroxide and extracted with benzene. The organic extract was dried and evaporated to give a pale yellow oil (31.93 g) of N-propyl-6-methoxy-1,2,3,4-tetrahydro-2-naphthylamine, NMR (CDCl3) δ 0.90 (t, 3H), 1.15 (s, 1H), 1.50 (m, 2H), 3.70 (s, 3H), 6.55 (s, 1H), 6.60 (d, 1H) and 6.90 (d, 1H).

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