Dimethylamine → 6-Dimethylamino-2-naphthaldehyde

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Reaction Steps

6-Methoxy-2-naphthaldehyde is prepared by successive treatment of 2-bromo-6-methoxynaphthalene in solution in dry ether with n-butyllithium and then dimethylformamide. (Literature: J. Med. Chem. 1998, 1308-1312). 6-Dimethylamino-2-naphthaldehyde is prepared according to the described procedure (Barbas et al., Proc. Natl. Acad. Sci. USA 1998, 95, 15351) as follows: gaseous dimethylamine is introduced into a mixture of 2.4 ml of dry benzene and 2.4 ml of hexamethylphosphoramide (HMPA) until 750 mg (16.7 mmol) is dissolved. At 0° C. and under inert atmosphere, n-butyllithium (1.6 M in hexane, 16.7 mmol) is added, then after 15 minutes, 6-methoxy-naphthaldehyde (390 mg, 2.09 mmol) is added. Stirring is continued for 14 hours at 20° C., then it is poured into aqueous phosphate buffer, pH 7.4, and it is extracted with ether. Purification by chromatography provides 6-dimethylamino-2-naphthaldehyde (350 mg, 84%).

Provenance & Evidence