ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
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-DioxidesReaction 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 CHCl3 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-(methylamino)benzenesufonamides 8,9, and 11 (Scheme 3) are obtained by naBH4 reduction of 5a and 10, respectively. Mechanisms for the thermal isomerization 5a → 10 and the NaBH4 reduction of 5a are proposed in Schemes 5 and 6.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19930760626
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