ISSN:
1434-193X
Keywords:
Thia-aza heterocycles
;
Bis(azolyl)alkanes
;
1-(Haloalkyl)pyridinium halides
;
Synthetic methods
;
Cyclization reactions
;
Ab initio calculations
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Novel 5/6/5 heterocycles, 1,3,4-thiadiazolo[3,2-a]-1,3,4-thiadiazolo[3,2-d]-1,3,5-triazinium halides 7, have been synthesized by the reaction of 2-amino-1,3,4-thiadiazoles 6 with either 1-(haloalkyl)pyridinium halides 4 or N,N′-methylenebis(pyridinium) dibromides 5. The tricyclic compounds 7 are generated in the course of several successive reaction steps in which specific proton migrations, bond-breaking and bond-forming processes occur. The structures 7 have been verified by spectral data (1H and 13C NMR, MS), X-ray analysis and ab initio calculations. The latter show that both sp2-C atoms C(10) and C(12) of 7 are significantly positively charged and, therefore, exhibit electrophilic properties towards the primary amino group of the amino-thiadiazoles 6. In the course of a multi-step reaction cascade of the 6/7 mixture, novel multi-aza/thia heterocycles 8 are formed. The structures of the latter compounds have been confirmed by X-ray analysis as well as by detailed experimental and theoretical NMR-spectroscopic studies.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
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