- Sulfur-Containing Heterocycles Derived by Reaction of ω-Keto Amides with Lawesson's Reagent
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The reaction of ω-keto amides with Lawesson's reagent (LR: 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide) is described. Treatment of 3-keto amides (2-acylacetamides) 1 with LR gave the corresponding 3-keto thioamides 2, along with 1,2-dithiole-3-thiones 3. Treatment of 4-keto amides, 3-acyl propionamides 5, with LR yielded five-membered heterocycles, pyrroles 6 and/or 2-aminothiophenes 7. 5-Keto amides, 3-benzoyl butyramides 8, reacted with LR to give dihydrothiopyran-2-thione 9 as the sole product, but in low yield. 2-Acylbenzamides 10 also reacted with LR to afford 3-mercaptoisoindolin-2-ones 11 or dihydroisobenzothiophene-1-thiones 12.
- Nishio, Takehiko
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- Utility involving thioacetoacetanilides as precursors for synthesis of new thiazole, thiadiazole and thiophene derivatives with antimicrobial activity
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The behavior of thioacetoacetanilide (1) and/or α-arylhydrazono-thioacetoacetanilides 4 toward many different α-halocarbonyl compounds was demonstrated. Thus, reactions of 1 with α-bromoketones (bromoacetone and phenacyl bromide) and hydrazonoyl bromides
- Fekri, Ahmed,Keshk, Eman M.
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p. 148 - 161
(2016/03/26)
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- Reactivity of α-acylated β-enamino ketones and esters: Synthesis of pyrazoles
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The reactivity of the enamino compounds 4-amino-3-phenylamino(thio)carbonyl-3-penten-2-one 1 and 2 and ethyl 3-amino-2-phenylamino(thio)carbonyl-2-butyrate 7 and 8 was studied using the reaction with hydrazine hydrate and hydrazine hydrochloride to evaluate the 1,3 electrophilic center of the compounds by the formation of the pyrazole rings. The pyrazoles 3,4,5,9,11 and 13 were obtained depending on the reaction conditions employed.
- Missio, Lauri J.,Braibante, Hugo S.,Braibante, Mara E. F.
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p. 1243 - 1245
(2007/10/03)
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- Studies on Isoxazoles. XI. Pyrolyses of 4-Isoxazolin-3-thiones
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Novel pyrolysis reactions of 4-isoxazolin-3-thiones (X) are described, affording two regioisomeric 1,4-dithiins (III, IV) and thioacetamides (XI).Among the thioacetamides, N-methylbenzoylthioacetamide (XIe) was identical with an authentic sample prepared by the reduction of 2-methyl-5-phenyl-4-isoxazolin-3-thione (Xe) with thiophenol.The structures of the dithiins were deduced from the physicochemical data, especially the shielding and deshielding effects in the NMR spectra.A mechanism for the reactions is proposed by analogy with the thermal isomerization of 3-isoxazolones into 2-oxazolones.In order to account for the formation of the isomeric dithiins, a thiirene intermediate (II) was assumed to be involved in the reaction pathway.Keywords- pyrolysis of 4-isoxazolin-3-thiones; thermal ring transformations; 1,4-dithiins; thioacetamides; thiirene intermediates; shielding and deshielding effects; sulfur radicals
- Sugai, Soji,Tomita, Kauzo
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p. 103 - 109
(2007/10/02)
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- Novel crotonanilides
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Novel crotonanilides of the formula STR1 wherein Z is selected from the group consisting of --O-- and --S--, R is selected from the group consisting of alkyl of 1 to 6 carbon atoms and optionally substituted phenyl, X and Y are individually selected from the group consisting of hydrogen, halogen, lower alkyl of 1 to 6 carbon atoms optionally substituted with at least one halogen, alkoxy of 1 to 3 carbon atoms, alkylthio and alkylsulfinyl of 1 to 6 carbon atoms, acyl of an organic carboxylic acid of 1 to 6 carbon atoms, --NO2 and --CF3, R1 is selected from the group consisting of hydrogen, chlorine, bromine, alkoxycarbonyl with 1 to 6 alkyl carbon atoms, nitro and alkylthio, alkylsulfinyl and alkylsulfonyl of 1 to 3 alkyl carbon atoms and R2 is alkyl of 1 to 6 carbon atoms, said compounds existing in the form of their E or Z isomers or mixtures thereof and having herbicidal properties.
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