In the first publication connected to this problem the 4-R-2-oxo-1,2-dihydroquinoline-3-carboxylic acids [3] were studied. The next step is to their amidated derivatives, and specifically in this report to 1-allyl-4-hydroxy-6,7-dimethoxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid alkylamides 1a-x.
The preparation of these substances was carried out by amidation of the methyl ester 2 by the corresponding alkylamines using a method which was decided by the physical properties of the amines used and their steric structure [4]. All of the alkylamide compounds obtained 1a-x are colorless, odorless, and tasteless, crystalline materials which are insoluble in water (Table 1). Their structure was confirmed by their 1H NMR spectra, the assignment of whose signals did not cause difficulty (Table 2)