Synthesis of Arylnaphthoquinones and Their Reactions with o‐Substituted Primary Aromatic Amines

Abstract

Cycloaddition reaction of 2‐aryl‐1,4‐benzoquinones 1a‐d with a number of different dienes, namely 2,3‐dimethylbutadiene; 1,4‐diphenylbutadiene and anthracene yield 2‐aryl‐6,7‐dimethyl‐1,4‐ naphthoquinones 3a,b; 2,5,8‐triphenyl‐1,4‐naphthoquinone 4 and 2‐aryl‐1,4,9,10‐tetrahydro‐9,10‐o‐benzoanthracene‐1,4‐dione 5, respectively were investigated. In addition, the cycloaddition reaction of 2‐aryl‐1,4‐benzoquinones 1d,e with 2,3‐dimethylbutadiene was also investigated to yield 2‐aryl‐5,8‐dihydro‐6,7‐dimethyl‐1,4‐naphthohydroquinones 2a,b. Cyclocondensation reactions of Diels‐Alder adducts 2b, 3b, 5a with ethylenediamine, o‐substituted primary aromatic amines gave quinoxaline, phenazine, phenoxazine and phenothiazine ocyclic derivatives 6–14.

Enzymatic cyclizations using laccases: Multiple bond formation between dihydroxybenzoic acid derivatives and aromatic amines

“…The formation of an ortho-quinone was postulated as an intermediate which further reacts with the diamine resulting in benzo[a]phenazin-5-ol. 28 The chemical synthesis of phenazines by amination and substitution of one hydroxyl group has been described by Fandy et al 29 Furthermore, 7 gives mainly 4 in the case of R 1 = OCH 3 or OC 2 H 5 and R 2 = CONH 2 and X = N, Y = CH, Z = NH. The ester groups of 1 undergo an addition-elimination reaction by the R 2 amino group and a loss of R 1 (reaction C, Scheme 7).…”

Arylnaphthoquinones. 8. Synthesis of 6-arylbenzo[a]phenazines

“…Практично важливою групою реакцій, що ведуть до утворення гетероциклічних сполук з атомами азоту у циклі, є взаємодія бензо-та нафтохінонів з аліфатичними й ароматичними діамінами та їхніми похідними [3]. Разом з тим, серед конденсованих азотовмісних гетероциклів знайдено практично корисні речовини, для яких зафіксовано протипухлинні, протипаразитарні, антимікробні та інші види біологічної активності [4].…”