Synthesis and Characterization of Dimethyl 9,10-Dihydro-9,10-dioxobenzoquinoline-2,4-dicarboxylate. Effect of the Pyrrole Nucleus on the Reactivity of Coenzyme PQQ

Article abstract of DOI:10.1021/jo00042a028

Dimethyl 9,10-dihydro-9,10-dioxobenzoquinoline-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 accom