N,1-Dialkyl-7-(alkylamino)-4-(alkylimino)-1,4-dihydroquinoline-3-carboxamides and Their 4-Oxo Derivatives: Synthesis and Properties

Methods are described for accessing the little known class of 4-alkyliminoquinoline-3- carboxamide title compounds 4; viz., from 4-oxoquinoline-3-carboxylic acids treated successively with thionyl chloride and amine, from 4-oxoquinoline-3-carboxylic esters treated likewise, and from the hydrogen chloride salt of a 4-alkyliminoquinoline-3-carboxylic ester and amine. Mechanistic aspects of the syntheses are discussed, and some spectroscopic and chemical properties of the title compounds are presented.