2,2'-Biquinoline誘導体に関する研究 (第4報)

Abstract

2-Bromocinchoninic acid (I), and methyl and ethyl 2-bromocinchoninate (IV) were prepared by application of phosphoryl bromide to 2-hydroxycinchoninic acid and its methyl and ethyl esters. Application of phosphorus pentabromide to these compounds afforded 2-bromocinchoninoyl bromide (VII) and then 2-bromocinchoninamide (VIII). Dimerization of (I) gave 2, 2′-bicinchoninic acid (II) and its methyl, ethyl, and propyl esters were prepared. These esters could not be obtained by dimerization of (IV) and (II) was formed. Application of thionyl chloride to (I) gave 2, 2′-bicinchoninoyl chloride which was derived to 2, 2′-bicinchoninamide. This amide was also obtained by dimerization of (VIII).Nine kinds of acid amide compounds of 2, 2′-bicinchoninic acid were prepared by application of ethylamine, isopropylamine, butylamine, aniline, dimethylamine, diethylamine, diisopropylamine, dibutylamine, and methylaniline to the acid chloride of 2, 2′-biquinoline.Permanganate oxidation of 4, 4′-dimethyl-2, 2′-biquinoline gave 4′-methyl-2, 2′-biquinoline-4-carboxylic acid (XIII) and a small amount of 2, 2′-bicinchoninic acid (II). Methyl and ethyl esters (XIV) of (XIII) were also prepared.