Synthesis and characterization of dimethyl 9,10-dihydro-9,10-dioxobenzo[f]quinoline-2,4-dicarboxylate. Effect of the pyrrole nucleus on the reactivity of coenzyme PQQ
作者:Shinobu Itoh、Yoshifumi Fukui、Shigenobu Haranou、Masaki Ogino、Mitsuo Komatsu、Yoshiki Ohshiro
DOI:10.1021/jo00042a028
日期:1992.7
Dimethyl 9,10-dihydro-9,10-dioxobenzo[f]quinoline-2,4-dicarboxylate (4) was synthesized, and its physical and chemical properties were compared to those of the trimethyl ester of PQQ (PQQTME, 2) and the 1-methyl derivative (3). The synthesis of 4 was accomplished by a Doebner-von Miller-type annulation between 3-amino-2-naphthol and dimethyl 2-oxoglutaconate and a subsequent oxidation with Fremy's salt. The electronic effect of the pyrrole nucleus of coenzyme PQQ (1) was examined by comparing the reactivity of 4 to that of 2 and 3 in the acetone adduct formation reaction, the redox reaction with phenylhydrazine, and the aerobic autorecycling oxidation of benzylamine. The significant role of the pyrrole nucleus in conducting the intramolecular general base catalysis in the amine oxidation is discussed.