4-Hydroxy-2-quinolines. 15. Synthesis of N-(2-pyridyl)amides of 1-R-4-hydroxy-2-quinolone-3-carboxylic acids as possible new non-steroidal antiinflammatory agents

4-Hydroxy-2-quinolones 132. Synthesis, chemical, and biological properties of 1-R-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acids 2-nitrobenzylidenehydrazides

“…Their formation may account for the extremely low rate of amidation, completion of which could not be achieved in the poorly solvating 2-propanol, even after increasing the reaction time to 10 days. A similar inertness towards nucleophiles, including amines, has also been demonstrated in sodium and potassium 1-R-3-ethoxycarbonyl-2-oxo-1,2-dihydroquinolin-4-olates [9]. The ammonium salts differ in their formation from a weak acid and weak bases (the 4-OH group in the ethyl 1-R-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylates 4 having a pKa of about 8.6 [10]), their separation from the reaction mixture occurring with rapid decomposition by the action of atmospheric moisture and carbon dioxide (as observed experimentally).…”

4-Hydroxy-2-quinolones 130. The reactivity of ethyl 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylates

“…None the less, the activating effect of the 4-OH group on the acylating properties of ester 1 is not in doubt since its removal, alkylation, participation in salt formation [11], or substitution by halogen, methyl [12], primary [13] or secondary [14] amino group fully deactivate the ester fragment. It was interesting that removal of the carbonyl group from position 2 of the quinoline ring produced a similar effect.…”

“…The ethoxycarbonyl group is placed virtually in the plane of the bicycle (torsional angles C (4) -C (3) -C (11) -O (3) -2.7(3), C (3) -C (11) -O (4) -C (12) 178.5(2), and C (11) -O (4) -C (12) -C (13) 172.0(2)º). This substituent location is likely due to the formation of an intramolecular hydrogen bond O (2) -H (2) Similar parameters were found in the 4-hydroxy-2-oxoquinoline ester 1 [6].…”

4-Hydroxy-1-methyl-2-oxo-N-(4-oxo-2-propyl-3,4-dihydroquinazolin-3-yl)-1,2-dihydroquinoline-3-carboxamide

“…In the present paper, we report the results of an investigation of the molecular and crystal structures of the (2-propyl-4oxoquinazoline-3-yl)amide of 1-methyl-4-hydroxy-2-oxo-1,2dihydroquinoline-3-carboxylic acid, (I), which may be used as ef®cient anti-in¯ammatory remedies (Ukrainets et al, 1993(Ukrainets et al, , 1994. Both bicyclic fragments of the molecule are planar.…”