9, 9'-ジアミノ-3, 3'-ジベンゾアントロニルおよび3, 3'-ジベンゾアントロニル-9, 9'-ジカルボン酸の合成

抄録

As bifunctional derivatives of 3, 3'-dibenzanthronyl, 9, 9'-diamine (1) and 9, 9'-dicarboxylic acid (2) were synthesized for the purpose of preparing new condensation polymers. Compound (1) was prepared as follows. m-Nitrobenzoyl chloride was treated with naphthalene by Friedel-Crafts reaction to give m-nitrophenyl naphtyl ketone (5), mp 125°C, in 30% yield. The ring closure of (5) proceeded at 100°C with a mixture of AlCl₃ and NaCl (5:1), then the reaction mixture was treated in the usual method and seperated chromatographically to give 9-nitrobenzanthrone (6) as pale yellow needles, mp 292°C, in 13.3% yield.
The dehydrogenation-condensation of (6) was performed under the conditions similar to those for the syntheses of 3, 3'-dibenzanthronyl and its halogen derivatives to give 9, 9'-dinitro-3, 3'-dibenzanthronyl (7), mp>460°C, in 20% yield, which was identified by i.r. spectra and elemental analysis.
(8) was reduced by Pd-charcoal and hydrazine hydrate in DMF, to give red violet crystalline powder, mp>500°C, which was identified as (1). (1) was also characterized by comparing with the product obtained by ammonolysis of 9, 9'-dichloro-3, 3'-dibenzanthronyl with 28% aq. ammonia in the presence of As₂O₅.
3, 3'-Dibenzanthronyl-9, 9'-dicarboxylic acid (2), mp 431°C, was synthesized by the oxidation of 9, 9'-dimethyl derivative (16) with KMnO₄ in pyridine. The structure of (2) was identified by elemental analysis, i.r. and mass spectrometry. (16) was prepared by the same method as (7), but with shorter reaction time, from 9-methylbenzanthrone (15), as pale yellow needles, mp 3836°C, in 20% yield. Ring closure of 1-naphthyl-m-toluylketone (14) proceeded easily according to Fieser, in 48% yield, but there remained some problems in the synthesis of intermediates, such as m-toluic acid.
Partial oxidation of m-xylene is known to give m-toluic acid (12) but in poor yields (less than 10%). We have oxidized m-xylene by dil-HNO₃ in the presence of Co salt of naphthenic acid, and obtained (12) (mp 112°C) in 17% yield. Friedel-Crafts condensation of m-toluyl chloride with naphthalene gave (14), mp 75°C, in 33% yield.