Desulfurization of 4-Nitro-N,2-diphenyl-3-(phenylamino)isothiazol- 5(2H)-imine: Formation of a 3-Imino-2-nitroprop-2-enamidine
| Autor: | Roland W. Kunz, Anthony Linden, Heinz Heimgartner, Dally Moya Argilagos |
|---|---|
| Přispěvatelé: | University of Zurich, Heimgartner, Heinz |
| Rok vydání: | 1998 |
| Předmět: |
10120 Department of Chemistry
1303 Biochemistry 1503 Catalysis Imine Ketene Biochemistry Medicinal chemistry Catalysis Inorganic Chemistry Amidine chemistry.chemical_compound Quinoxaline Amide 540 Chemistry Drug Discovery Organic chemistry Physical and Theoretical Chemistry Thioamide chemistry.chemical_classification Nucleophilic addition 1604 Inorganic Chemistry 3002 Drug Discovery Thiophenol Organic Chemistry chemistry 1606 Physical and Theoretical Chemistry 1605 Organic Chemistry |
| Zdroj: | Helvetica Chimica Acta. 81:2388-2406 |
| ISSN: | 1522-2675 0018-019X |
| DOI: | 10.1002/(sici)1522-2675(19981216)81:12<2388::aid-hlca2388>3.0.co;2-h |
| Popis: | The course of the desulfurization reaction of 4-nitro-N,2-diphenyl-3-(phenylamino)isothiazol-5(2H)-imine (3) is investigated and the formation of the unstable 3-imino-2-nitroprop-2-enamidine (A) as intermediate is discussed. Addition of amines and thiophenol to the reaction mixture yielded the amidine derivatives 5 and the thioimidate 6, respectively, via nucleophilic addition of the respective reagent to A (Scheme 2). Benzoic acid and thiobenzoic acid afforded the amide 7 and the thioamide 8, respectively, as secondary products of the expected adducts 7a and 8a (Schemes 3 and 4). The presence of (benzylidene)(methyl)amine in the reaction mixture of the desulfurization of 3 led to the 1,2,4-oxadiazole derivative 10, together with the quinoxaline N-oxide 4 as a minor product. Reaction mechanisms involving an intermediate ketene imine and participation of the NO2 group in the reaction leading to 1,2,4-oxadiazole 10 are proposed. Ab initio calculations of model structures for the nitroketene imine were performed and the results correlated with the experimental results. The structures of 8 and 10 were established by X-ray crystal-structure analysis. |
| Databáze: | OpenAIRE |
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