Dimethylamine → 1-(6-(Dimethylamino)naphthalen-2-yl)ethanone

Participants

Reaction Steps

To a solution of 5.26 g (117 mmol) of dimethylamine in 29 mL of freshly distilled hexamethylphosphoric triamide (HMPT) were added 31 mL of dry toluene and 780 mg (112 mmol) of Li in small pieces. The mixture was stirred under argon at room temperature for 1.5 hours. 2-Acetyl-6-methoxynaphthalene was prepared as described in Arsenijevic et al., Org. Synth. Coll. 1988, 6:34-36, the disclosure of which is incorporated herein by reference. 2-Acetyl-6-methoxynaphthalene (5.57 g, 27.8 mmol) was added in one portion, and stirring was continued for 20 hours. The mixture was cooled in an ice-water bath and poured into a cold water/ethyl acetate mixture (300 mL each). After thorough mixing, the layers were separated, and the water layer was extracted twice with 225 mL of ethyl acetate. Organic extracts were combined, dried, and evaporated to give a yellow solid. Recrystallization from ethanol afforded 3.67 g (64%) of 2-acetyl-6-(dimethylamino)naphthalene (ADMAN) as a yellow solid, melting at 153.5-155° C.: 1H NMR (CDCl3, TMS) δ2.67 (s, 3H, COCH3), 3.15 (s, 6H, N(CH3)2), 6.87 (d, 1H, H-5), 7.17 (dd, 1H, H-7), 7.63 (d, 1H, H-4), 7.80 (d, 1H, H-8), 7.92 (dd, 1H, H-3), 8.32 (bs, 1H, H-1). J1,3=2.3 Hz, J5,7=2.4 Hz, J7,8=9.3 Hz. MS (M+) 213: found: 213. Anal. Calcd for C4H15NO: C, 78.84: H, 7.09; N, 6.57. Found C, 78.96; H, 7.10; N, 6.45.

Provenance & Evidence