Thienoanellierte 6a?4-Thia-1,6-diazapentalene durch baseninduzierte Dimerisierung von 5-Methyl-isothiazoliumsalzen
摘要:
Isothiazolium salts 2 and 3 are easily available by reaction of (Z/E)-beta-thiocyanatovinyl aldehydes with primary aliphatic and aromatic amines in acetic acid or with aromatic amine hydrochlorides, respectively. Preparative advantages of this reaction are demonstrated and discussed. Reaction of 3 with secondary amines results in an unexpected formation of 6a-lambda-4-thia-1,6-diazapentalenes 5, a new typ of thiadiazapentalenes anellated with a heterocyclic ring system. The structure of 5 was evidenced by IR, UV, H-1-, C-13-n.m.r. spectral data and supported by elemental analysis. By means of N-15- and C-13-n.m.r. spectroscopy the synthesized thiadiazapentalenes were found to be stable towards protonation.
Thienoanellierte 6a?4-Thia-1,6-diazapentalene durch baseninduzierte Dimerisierung von 5-Methyl-isothiazoliumsalzen
摘要:
Isothiazolium salts 2 and 3 are easily available by reaction of (Z/E)-beta-thiocyanatovinyl aldehydes with primary aliphatic and aromatic amines in acetic acid or with aromatic amine hydrochlorides, respectively. Preparative advantages of this reaction are demonstrated and discussed. Reaction of 3 with secondary amines results in an unexpected formation of 6a-lambda-4-thia-1,6-diazapentalenes 5, a new typ of thiadiazapentalenes anellated with a heterocyclic ring system. The structure of 5 was evidenced by IR, UV, H-1-, C-13-n.m.r. spectral data and supported by elemental analysis. By means of N-15- and C-13-n.m.r. spectroscopy the synthesized thiadiazapentalenes were found to be stable towards protonation.
Ring Transformations of 4,5- to the Isomeric 3,4-Disubstituted Isothiazolium Salts and their oxidation to 1,1-dioxides
作者:Antje Noack、Svea Jelonek、Fernando B. Somoza、B�rbel Schulze
DOI:10.1002/prac.19983400411
日期:——
4,5-Disubstituted N-phenyl-isothiazolium salts 1 with active 5-methyl group react under the influence of anilines to form 3,4-disubstituted isothiazolium salts 3. The influence of donor and acceptor substituents in the 2-phenyl group of 1a-h and in the anilines 2 on the ring transformation were studied. The structure of the new salts was confirmed by X-ray analysis. The 3-hydroperoxy-2,3-dihydro-isothiazole 1,1-dioxides (12a,d)and the isothiazole-3(2H) -one 1,1-dioxides (14a,d) are obtained by oxidation of salts 3 with H2O2.
Thienoanellierte 6a?4-Thia-1,6-diazapentalene durch baseninduzierte Dimerisierung von 5-Methyl-isothiazoliumsalzen
Isothiazolium salts 2 and 3 are easily available by reaction of (Z/E)-beta-thiocyanatovinyl aldehydes with primary aliphatic and aromatic amines in acetic acid or with aromatic amine hydrochlorides, respectively. Preparative advantages of this reaction are demonstrated and discussed. Reaction of 3 with secondary amines results in an unexpected formation of 6a-lambda-4-thia-1,6-diazapentalenes 5, a new typ of thiadiazapentalenes anellated with a heterocyclic ring system. The structure of 5 was evidenced by IR, UV, H-1-, C-13-n.m.r. spectral data and supported by elemental analysis. By means of N-15- and C-13-n.m.r. spectroscopy the synthesized thiadiazapentalenes were found to be stable towards protonation.