Synthèses dans le domaine des hydrocarbures cancérigènes‐VIII 1,2,3,4‐Dibenzotétracène et para‐quinones (‐5,12 et‐6,11) correspondantes

Summary - A new synthesis of 1,2,3,4-dibenztetracene (VII) has been devised. This synthesis involves the following steps: condensation of naphthalene-2,3-dicarboxylic anhydride with 9-phenanthrylmagnesium bromide [3(9′-phenanthroyl)-2-naphthoic acid (V)], cyclisation with benzoyl chloride containing a small amount of conc. H2SO4 [1,2,3,4-dibenztetracenequinone-5,12 (VI)], reduction with Zn, acetic acid and pyridine [1,2,3,4-dibenztetracene (VII)]. Oxidation of this hydrocarbon with chromic acid, gave the isomeric 1,2,3,4-dibenztetracenequinone-6,11 (VIII), previously prepared by E. Clar.