4-Hydroxy-3-nitro-2-quinolones and related compounds as inhibitors of allergic reactions

Abstract

The synthesis and biological activity of a number of 4-hydroxy-3-nitro-2-quinolones are discussed and compared with their related hydroaromatic analogs. Antiallergic activity has been assessed by their ability to inhibit the homocytotropic antibody-antigen induced passive cutaneous anaphylaxis reaction in the rat.

Synthesis and SAR studies of novel 6,7,8‐substituted 4‐substituted benzyloxyquinolin‐2(1H)‐one derivatives for anticancer activity

“…A general synthetic approach to the key intermediate 4‐hydroxyquinolin‐2(1 H )‐one is the Knorr quinoline synthesis, which involves cyclization and dehydration of a transient β‐ketoanilide, formed by condensation of a β‐keto ester and aniline at relatively high temperature. More specific synthetic approaches include cyclization of N ‐acetylanthranilic acid derivatives (Buckle et al ., ), condensation of malonates/malonic acid with anilines using ZnCl 2 and POCl 3 (Zhang et al ., ; Priya et al ., ), Ph 2 O (Ahvale et al ., ) and cyclization of malonodianilides with PPA (Cai et al ., ; Park et al ., ; Moradi‐e‐Rufchahi, ), CH 3 SO 3 H/P 2 O 5 (Kappe et al ., ) and p ‐toluenesulfonic acid (Nadaraj et al ., ). In our study, 4‐hydroxyquinolin‐2(1 H )‐one derivatives ( 5a–i ) were synthesized by treatment of a substituted aniline ( 1a–i ) with diethylmalonate ( 2 ) in one flask (Mohamed, ; Arya and Agarwal, ), followed by cyclization of the formed monoanilide ( 3a–i ) or malondianilide ( 4a–i ) precursors in the presence of PPA.…”

Novel Neuronal Nitric Oxide Synthase (nNOS) Selective Inhibitor, Aplysinopsin-Type Indole Alkaloid, from Marine Sponge Hyrtios erecta.

“…The isolation of compound 6 from a natural source is reported for the first time, but 6 has been already reported as a synthetic compound without NMR assignment. 12) Compound 7 was also isolated as a yellow powder. The EI-MS of 7 showed the molecular ion at m/z 317/319/321, implying the existence of two bromine atoms.…”

An Expeditious Copper‐Catalyzed Access to 3‐Aminoquinolinones, 3‐Aminocoumarins and Anilines using Sodium Azide

“…1 H and 13 C NMR spectra were measured in CDCl 3 or DMSO-d 6 with a Bruker Avance-300. 1 H chemical shifts are reported in ppm from an internal standard TMS or of residual chloroform (7.27 ppm).…”

“…The conventional route to prepare 3-aminoquinolinones is the sequential nitration/reduction of 4-hydroxyquinolinones into 3-amino-4-hydroxyquinolinones. [6] However, the protocol is limited to substrates having a C-4 hydroxy substituent. Alternative routes consist of the Hofmann rearrangement of quinolinone-3-carboxylic acid derivatives, [4] or cyclization of a suitable N-chloroacetyl-ortho-aminobenzophenone precursor to form an a-pyridinium salt followed by hydrazinolysis.…”