ChemInform Abstract: Synthesis and Antitubercular Activity of 4‐Pyridylglyoxylic Acid Derivatives.

Abstract

ChemInform Abstract Oxidation of the ethylpyridines (I) with potassium permanganate yields predominantly the pyridine carboxylic acids (III), together with minor amounts of the pyridylglyoxylic acids (II). The 3-pyridyl compound (IIa) is coupled with the phenylhydrazine (IV) to form the nicotinaldehyde hydrazone (V) as the result of a decarboxylation, whereas the 4-pyridylglyoxylic acid (IIb) gives the usual carbonyl reactions. The semicarbazones (VIII) are cyclized, producing the triazinones (IX). The quinoxalinone (XI) is obtained from (IIb) and o-phenylenediamine (X).