ISSN:
0749-1581
Keywords:
Polyazaindolizines
;
Protonation
;
13C NMR
;
1H NMR pK values
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The pKa, values of six sulmazole analogues were measured spectrophotometrically. The major protonation sites for most of these bridgehead nitrogen heterocycles were determined by 1H and 13C NMR methods. The aryl-substituted imidazo[1,2-a]pyrimidine (4), 8-methoxyimidazo[1,2-a]pyrazine (6), imidazo[1,2-b]pyridazine (9) and imidazo[1,2-b][1,2,4]triazine (11) undergo protonation at the imidazo nitrogen. The imidazo[1,2-a]pyrazine (5) protonates mainly at N-7. In some cases differences in basicity properties between these aryl analogues and the bridgehead heterocycles have been observed.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260290511
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