A Convenient Synthesis of Certain Benzo and Dibenzoxanthones and Chromones

Abstract

Certain chromones and benzoxanthones were prepared by heating at 300–325° a mixture of 1‐or 2‐naphthol with either phenyl o‐hydroxybenzoate or o‐hydroxynaphthoate or a β‐ketoester. The yields and purity of the products are superior to those obtained by the published procedures.

Efficient Synthesis of a New L-Shaped Dimer of Naphthalene, and Its Analogs

“…7H-Dibenzo[c,h]xanthen-7-one (4) is a known compound synthesized by the reaction naphthol and hydroxynaphthoate. 7) We did not obtain dimer 4 by treatment of 3 in PPA at 100 C for 8 h. This result indicates that dimer 4 is formed from an A possible mechanism is shown in Scheme 3. Dimer 3 was a new compound, and hence we determined its structure by extensive 2D NMR analysis ( Table 1).…”