Reactions of heteroaromatic thiols with 1,3-butadiene and cyclopentadiene

Анисимов, А. В.; Babaitsev, V. S.; Kolosova, T. A.; Viktorova, E. A.

doi:10.1007/bf00503185

Cited by 2 publications

(6 citation statements)

References 3 publications

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“…Yield 0.17 g (68%). Light-yellow crystals, mp 89-91°C (95-96°C [4]), R f 0.17 (ethyl acetate-hexane, 1:2). 1 Compounds VIIb-VIIf were similarly obtained.…”

Section: -(2-hydroxy-3-nitro-5-chlorophenyl)-123-thiadiazole (Iiih)mentioning

confidence: 99%

“…Among the derivatives of benzo[b]furan-2-thiols only the unsubstituted benzo[b]furan-2-thiol, 3-allylbenzofuran-2-thiol, and several 2-sulfanylbenzo[b]furan-3-aldehydes [1][2][3][4][5][6][7][8] have been known up till now. The benzo [b] furan-2-thiol was prepared by metallation of benzo [b] furan with butyllithium followed by the treatment with sulfur and acidifying to obtain benzo-[b]furan-2-thiol [1,4].…”

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confidence: 99%

“…The benzo [b] furan-2-thiol was prepared by metallation of benzo [b] furan with butyllithium followed by the treatment with sulfur and acidifying to obtain benzo-[b]furan-2-thiol [1,4]. 2-Sulfanylbenzo[b]furan-3-aldehydes were synthesized from 2-halobenzo[b]furan-3-aldehydes under the action of sodium hydrogen sulfi te [6,7].…”

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confidence: 99%

“…3-Allylbenzofuran-2-thiol was obtained by the rearrangement of allyl 2-benzofuryl sulfi de [8]. The benzo[b]furan-2-thiol derivatives exhibit a biological action [1] and are used in the organic synthesis [1][2][3][4][5][6][7].…”

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Synthesis of benzo[b]furan-2-thioles from 4-(2-hydroxyaryl)-1,2,3-thiadiazoles

et al. 2012

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4-(2-Hydroxyaryl)-1,2,3-thiadiazoles treated with bases decompose with nitrogen liberation and the formation of benzo[b]furan-2-thiolates. On acidifying the thiolates benzo[b]furan-2-thiols were obtained. 4-(4-and -5-Benzyloxy-2-hydroxyphenyl)-1,2,3-thiadiazoles formed analogously the corresponding benzo[b]furan-2-thiolates whose acidifying afforded polymeric compounds. Among the derivatives of benzo[b]furan-2-thiols only the unsubstituted benzo[b]furan-2-thiol, 3-allylbenzofuran-2-thiol, and several 2-sulfanylbenzo[b]furan-3-aldehydes [1-8] have been known up till now. The benzo[b] furan-2-thiol was prepared by metallation of benzo[b] furan with butyllithium followed by the treatment with sulfur and acidifying to obtain benzo-[b]furan-2-thiol [1, 4]. 2-Sulfanylbenzo[b]furan-3-aldehydes were synthesized from 2-halobenzo[b]furan-3-aldehydes under the action of sodium hydrogen sulfi te [6, 7]. 3-Allylbenzofuran-2-thiol was obtained by the rearrangement of allyl 2-benzofuryl sulfi de [8]. The benzo[b]furan-2-thiol derivatives exhibit a biological action [1] and are used in the organic synthesis [1-7].We have developed a new method for the preparation of both unsubstituted and substituted in the aromatic ring benzo[b]furan-2-thiols from available 4-(2-hydroxyaryl)-1,2,3-thiadiazoles IIIa-IIIh. 1,2,3-Thiadiazoles IIIaIIIc were obtained from 2-hydroxyacetophenones Ia-Ic through the formation of the corresponding ethoxycarbonylhydrazones IIa-IIc with subsequent treatment with thionyl chloride [9]. 1,2,3-Thiadiazoles IIId-IIIf were obtained similarly.4-(2-Hydroxy-3-iodo-5-chlorophenyl)-1,2,3-thiadiazole (IIIg) and 4-(2-hydroxy-3-nitro-5-chlorophenyl)-1,2,3-thiadiazole (IIIh) were prepared by iodination and nitration respectively of 4-(2-hydroxy-5-chlorophenyl)-1,2,3-thiadiazole (IIId). R OH O CH 3 R OH NNHCO 2 Et CH 3 R OH NH 2 NHCO 2 Et SOCl 2 S N N IIIа _ IIIf IIа _ IIf Iа _ If R = H (a), 4-Me (b), 5-Me (c), 5-Cl (d), 4-BnO (e). 5-BnO (f).4-(2-Hydroxyaryl)-1,2,3-thiadiazoles IIIa-IIIh under the action of a base (potassium carbonate) in anhydrous DMF (thiadiazole IIIh at treatment with potassium tertbutylate in anhydrous THF) decomposed with nitrogen evolution and the formation of potassium 2-(2-hydroxyaryl)ethynethiolate IVa-IVh. Further the intramolecular proton transfer provided thioketene derivatives Va-Vh. As a result of the intramolecular cyclization involving the hydroxy group and the thioketene fragment followed by acidifying of anions VIa-VId, VIg, VIh we obtained benzo[b]furan-2-thiols VIIa-VIIf.The structure of compounds VIIa-VIIf was proved by 1 H, 13 C NMR and mass spectra by the coincidence of the constants with the published data and by reactions of

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“…Yield 0.17 g (68%). Light-yellow crystals, mp 89-91°C (95-96°C [4]), R f 0.17 (ethyl acetate-hexane, 1:2). 1 Compounds VIIb-VIIf were similarly obtained.…”

Section: -(2-hydroxy-3-nitro-5-chlorophenyl)-123-thiadiazole (Iiih)mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Synthesis of benzo[b]furan-2-thioles from 4-(2-hydroxyaryl)-1,2,3-thiadiazoles

et al. 2012

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“…The benzo[b]furan-2-thiol proper is obtained by the metallation of benzo[b]furan with butyllithiun followed by treating with sulfur and isolating the benzo[b]furan-2-thiol by acidification [1,4]. 2-Sulfanylbenzo[b]furan-3-aldehydes were prepared from 2-halobenzo[b]furan-3-aldehydes and sodium hydrosulfite [6,7].…”

mentioning

confidence: 99%