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The (1H-Tetrazol-1-yl)arenediazonium Salts as Convenient Reagents for Quinones Arylation: Synthesis of 1,3-Benzoxathiol-2-ones and Naphtho[2,1-d][1,3]oxathiol-2-ones Bearing (1H-Tetrazol-1-yl)phenyl Motif

“…53 However, in our opinion, the most convenient and quite promising onestage method for obtaining 1,3-benzoxathiols is the reaction of quinones with thiourea. [58][59][60] The substituted 1,4-quinones 4a-f readily react with thiourea at room temperature in the presence of a strong mineral acid to form intermediate isothiuronium salts, which cyclize with high yields to 5-hydroxy-1,3benzoxathiol-2-ones 8a-f under heating (Scheme 5). It should be noted that the high reactivity of tetrazolylarylquinones indicates their synthetic potential, which can be realized in a number of transformations.…”

Synthesis of heterocycles on the basis of arylation products of unsaturated compounds: XX. Reaction of 2-aryl-1,4-benzoquinones with potassium O-butyl carbonodithioate

“…Also, a few published data are available on reactions of nucleophiles with 2-aryl-1,4-benzoquinones, though the latter can readily be obtained by arylation of 1,4-benzoquinone with arenediazonium chlorides [12,13] or other reagents [14][15][16]. We previously showed that reactions of 2-aryl-1,4-benzoquinones with thiourea in acid medium are selective [17]: nucleophilic attack is directed at position 6 of the quinone ring. Intermediate thiuronium salt thus formed undergoes intramolecular cyclization with formation of 7-aryl-5-hydroxy-1,3-benzoxathiol-2-ones.…”

“…Theoretically, three isomeric compounds A-C (Scheme 1) could be formed, depending on the regioselectivity of primary addition of nucleophile II to quinones I. The reactions of arylquinones with thiourea gave 7-aryl-5-hydroxy-1,3-benzoxathiol-2-ones as analogs of isomer A [17]. Analysis of the 1 H NMR and mass spectra of the products showed that 2-aryl-1,4-benzoquinones Ia-Ig reacted with potassium O-butyl carbonodithioate less selectively than with thiourea.…”

Heterocycles Synthesis Based on Arylation Products of Unsaturated Compounds: XII. Reactions of 2-Aryl-1,4-benzoquinones with Dithiol Compounds

“…As for the reactions of the monoarylsubstituted 1,4-benzoquinones with S-nucleophilic reagents, the main point of attack is the position 6 of the quinone ring [4,19]. In the present study we investigated the trends in the regioselectivity of addition of some dithiocarboxylic acids derivatives to 2-aryl-1,4-benzoquinones.…”

“…The regioselectivity of the nucleophilic attack in the reaction of 2-aryl-1,4-benzoquinones with thiourea occurring in acid medium [19] may be due to the prevailing protonation of the carbonyl group in the position 4. Then the electron density distribution in the quinone ring favors the nucleophile addition to the position 6.…”