1-Naphthaldehyde → HCID 1713297, compound

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Reaction Steps

Compound 2 is prepared by the condensation of sodium α-napththylacetate with α-naphthaldehyde in acetic anhydride at 130° C for 8 hours. Some trans-1,2-di(1-naphthyl)ethylene is produced from the reaction and is crystallized from alcohol to yield a yellow crystalline solid, mp. 162°-163° C. Elemental analysis C 94.2, H 5.9, calculated for C22H16, C 94.3, H 5.7. The infrared spectrum of the product is consistent with this product's structure. The principal product of condensation is 2,3-di(1-naphthyl)acrylic acid which is isolated and purified by recrystallization from water as its sodium salt. The free acid (7 percent yield) is recrystallized from acetic acid. A relatively low yield may in part be accounted for by some difficulties in phase separation in the workup. The method used for preparation of compound 2 likely would have provided a higher yield, but this procedure is appropriate to permit isolation of the cis-olefin on decarboxylation of the acrylic acid. The acid is decarboxylated by heating in boiling quinoline with copper chromite catalyst for 1 hour. The resulting product, which appears to be mainly the desired cis-isomer contaminated with a small amount of trans, has mp. 98-105 C; the literature value is 103-104 C (Everett et al, J. Chem. Soc., 601 (1948).

Provenance & Evidence