Propanoic acid, 2-bromo-2-methyl-, ethyl ester → 6-Methoxy-2-naphthaldehyde

Beteiligte Stoffe

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6-methoxy-2-naphthaldehyde (substrate IIA) was synthesized from 6-methoxy-2-carbethoxynaphthalene, prepared from 6-methoxy-2-naphthonitrile, ethyl 2-bromoisobutyrate, and zinc dust as described by Horeau et al., 1947, Bull. Soc. Chim. Fr. 14:53-59. The keto-ester intermediate, mp 74°-76° C. (lit. 72.5-73.5° C.) was reduced to the corresponding secondary alcohol ester with sodium borohydride in ethanol at 4° C. and then thermally decomposed (Horeau et al. 1953, Compt. Rend. 236:826-8) to afford the final compound. The aldehyde was 25 purified either by zone sublimation or via the bisulfite adduct; mp 80°-81.5° C.; (lit. 79° C. Horeau et al., 1953, supra: lit. 81°-82° C. Gandhi et al., 1955 J. Chem. Soc., 2530).

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