Synthesis of 2(1H)-Quinolinonequinones and 2-Alkoxyquinolinequinones Using Oxidative Demethylation with Cerium (IV) Ammonium Nitrate

Abstract

A b s t r a c t -2,5,8(1H)-Quinolineuiones (12), 2,5,6(1H)-quinolineuiones (13), 2-alkoxy-5,8-quinolinediones (14). 2.8-dimethoxy-5,6-quinolinedione (15). and 2,6-dimethoxy-7,8-quinolinediones (16) were synthesized by oxidative demethylation of the corresponding 2(1H)-quinolinones (7) and Zalkoxyquinolines (11) with cerium (IV) ammonium nimte.Streptonigrin (I), a highly substituted 5.8-quinolinedione, was first reported as an antitumor antibiotic produced by Streptomycesflocculus.l It was later found to be one of the most potent inhibitors of avian myeloblastosis virus reverse transcriptase (AMV-RT), but its remarkable cytotoxic activity seemed to be disadvantageous with respect to a specific inhibitor of retroviru~.~ Recently, we observed that synthetic 6-methoxy-5,8-quinoline-

Synthesis of Casimiroin and Optimization of Its Quinone Reductase 2 and Aromatase Inhibitory Activities

“…Colorless solid: mp 90–92 °C (lit37 mp 92–93 °C). IR (KBr) 3300, 2800, 1714, 1668, 1534, 1465, 1405, 1342, 1219, 1203, 1031, 750 cm −1 ; 1 H NMR (CDCl 3 , 300 MHz) δ 9.02 (brs, 1 H), 7.97 (s, 1 H), 6.46 (s, 1 H), 3.78 (s, 3 H), 3.76 (s, 3 H), 3.73 (s, 3 H), 3.49 (s, 2 H), 2.23 (s, 3 H); 13 C NMR (CDCl 3 , 75 MHz) δ 204.2, 162.9, 145.0, 142.3, 120.2, 105.4, 97.3, 56.5, 56.2, 50.3, 30.8; EIMS ( m/z , relative intensity) 267 (M + , 64), 252 (5), 209 (44), 194 (32), 168 (100), 140 (28), 108 (13), 69 (15); HRMS calcd for C 13 H 17 NO 5 267.1107, found 267.1106.…”

Facile Oxidation of Fused 1,4-Dimethoxybenzenes to 1,4-Quinones Using NBS: Fine-Tuned Control over Bromination and Oxidation Reactions

“…Although oxidation of 1,4-hydroquinones is much easier than that of 1,4-dimethoxybenzenes, the direct oxidation route (path a) is much more attractive over path b as a result of the difficulty in the demethylation reaction and the isolation of 1,4-hydroquinones. Several examples of path a reported that oxidative demethylation affords quinones from dimethoxybenzenes using ceric ammonium nitrate (CAN), argentic oxide, and concentrated nitric acid . Oxidative demethylation using nitric acid gave low yield as a result of vigorous conditions and also side reactions such as nitration of the aromatic ring and oxidative demethylation.…”

Synthesis, Molecular Mechanism and Pharmacokinetic Studies of New Epoxy Lignan‐Based Derivatives

“…Structural modification of natural compounds should be environmentally free of metal traces. In organic chemistry, oxidative demethylation can be performed using nitric acid , silver(II) oxide (AgO)‐mineral acid , cerium(IV) ammonium nitrate (CAN) , NBS‐H 2 SO 4 and cobalt(III) fluoride (COF 3 ) . Tohma et al reported that polymer‐supported hypervalent iodine reagents replaced highly toxic metal oxidants due to their low toxicity and high yield.…”