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Ringerweiterung von sechs- zu neungliedrigen Heterocyclen: Umsetzung von 3-(Dimethylamino)-2,2-dimethyl-2H-azirin mit 3,4-Dihydro-2H-1,2,4-benzothiadiazin-3-on-1,1-dioxid


Schläpfer-Dähler, Marlise; Heimgartner, Heinz (1993). Ringerweiterung von sechs- zu neungliedrigen Heterocyclen: Umsetzung von 3-(Dimethylamino)-2,2-dimethyl-2H-azirin mit 3,4-Dihydro-2H-1,2,4-benzothiadiazin-3-on-1,1-dioxid. Helvetica Chimica Acta, 76:2398-2406.

Abstract

Ring Enlargement of Six- to Nine-Membered Heterocycles: Reaction of 3-(Dimethylamino)-2,2-dimethyl-2H-azirine with 3,4-Dihydro-2H-1,2,4-benzothiadiazin-3-one 1,1-Dioxides. Reaction of 3-(dimethylamino)-2,2-dimethyl-2H-azirine (1) and N-substituted 3,4-dihydro-2H-1,2,4-benzothiadiazin-3-one 1,1-dioxides (4) in CHCI3 yields 3-(dimethylamino)-4,5,6,7-tetrahydro-1,2,5,7-benzothiatriazonin-6-one 1,1-dioxides 5, a novel nine-membered heterocyclic system, by ring enlargement (Schemes 2 and 4). In refluxing MeOH, the heterocycle 5a rearranges to give the N-[1-methyl-1-(1,1-dioxo-4H-1,2,4-benzothiadiazin-3-yl)ethyl]-N’,N’-dimethylurea 10. The three isomeric 2-(methyl amino)benzenesulfonamides 8, 9, and 11 (Scheme 3) are obtained by NaBH4 reduction of 5a and 10, respectively. Mechanisms for the thermal isomerization 5a to 10 and the NaBH4 reduction of 5a are proposed in Schemes 5 and 6 .

Abstract

Ring Enlargement of Six- to Nine-Membered Heterocycles: Reaction of 3-(Dimethylamino)-2,2-dimethyl-2H-azirine with 3,4-Dihydro-2H-1,2,4-benzothiadiazin-3-one 1,1-Dioxides. Reaction of 3-(dimethylamino)-2,2-dimethyl-2H-azirine (1) and N-substituted 3,4-dihydro-2H-1,2,4-benzothiadiazin-3-one 1,1-dioxides (4) in CHCI3 yields 3-(dimethylamino)-4,5,6,7-tetrahydro-1,2,5,7-benzothiatriazonin-6-one 1,1-dioxides 5, a novel nine-membered heterocyclic system, by ring enlargement (Schemes 2 and 4). In refluxing MeOH, the heterocycle 5a rearranges to give the N-[1-methyl-1-(1,1-dioxo-4H-1,2,4-benzothiadiazin-3-yl)ethyl]-N’,N’-dimethylurea 10. The three isomeric 2-(methyl amino)benzenesulfonamides 8, 9, and 11 (Scheme 3) are obtained by NaBH4 reduction of 5a and 10, respectively. Mechanisms for the thermal isomerization 5a to 10 and the NaBH4 reduction of 5a are proposed in Schemes 5 and 6 .

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Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Language:German
Date:1993
Deposited On:26 Dec 2013 09:45
Last Modified:08 Dec 2017 01:33
Publisher:Wiley-Blackwell
ISSN:0018-019X
Funders:Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung, F. Hoffmann-La Roche AG, Basel

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