ISSN:
0030-4921
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 13C NMR spectra of a number of pyridazine derivatives have been recorded in DMSO-d6 solution and analysed. Examination of the most diagnostic resonances, with particular emphasis on those arising from the pyridazine ring system, enabled the ready establishment of the presence of a ring-chain tautomerism in 5-(o-aminophenylcarbamoyl)pyridazine-4-carboxylic acid, methyl 5-(o-aminophenylcarbamoyl)pyridazine-4-carboxylate, 5-(o-aminophenylcarbamoyl)-3,6,-dimethylpyridazine-4-carboxylic acid and 5-(2-amino-1,2-dicyanovinylenecarbamoyl)pyridazine-4-carboxylic acid. This gave rise to 3′,4′-dihydro-3′-oxospiro[pyridazine-5(2H),2′(1H)-quinoxaline]-4-carboxylic acid, methyl 3′,4′-dihydro-3′oxospiro[pyridazine-5(2H),2′(1′H)-quinoxaline]-4-carboxylate, 3′,4′-dihydro-3′-oxo-3,6-dimethylspiro[pyridazine-5(2H), 2′(1′H)-quinoxaline]-4-carboxylic acid and 5-oxo-2,3-dicyano-1,4,8,9-tetraazaspiro[5.5]undeca-2,7,10-triene-11-carboxylic acid, respectively.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/omr.1270210111
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