A1 Refereed original research article in a scientific journal
Condensation of triformylmethane with heteroaromatic amines, including nucleic acid bases. A novel example of ring-chain tautomerism
Authors: Neuvonen K, Zewi C, Lonnberg H
Publisher: MUNKSGAARD INT PUBL LTD
Publication year: 1996
Journal:: Acta Chemica Scandinavica
Journal name in source: ACTA CHEMICA SCANDINAVICA
Journal acronym: ACTA CHEM SCAND
Volume: 50
Issue: 12
First page : 1137
Last page: 1142
Number of pages: 6
ISSN: 0904-213X
DOI: https://doi.org/10.3891/acta.chem.scand.50-1137
Abstract
Treatment of several heteroaromatic amines, including the nucleic acid bases cytosine and adenine, with triformylmethane in pyridine at 70 degrees C afforded 1:1 condensation products (2-11) that were characterized by H-1 and C-13 NMR spectroscopy. All the compounds were assigned as N-substituted aminomethylenemalonaldehydes, strongly preferring the amino/keto form over the imino/enol tautomer. With cytosine and 1-methylcytosine, unequivocal evidence for ring-chain tautomerism was additionally obtained: intramolecular nucleophilic attack of cytosine N3 to one of the carbonyl carbons results in reversible cyclization to a 4-hydroxy-4H-pyrimido[1,6-a]pyrimidin-6(7H)-one derivative (9b, 10b). In dry methanol the corresponding O-methyl ether (12) was obtained.
Treatment of several heteroaromatic amines, including the nucleic acid bases cytosine and adenine, with triformylmethane in pyridine at 70 degrees C afforded 1:1 condensation products (2-11) that were characterized by H-1 and C-13 NMR spectroscopy. All the compounds were assigned as N-substituted aminomethylenemalonaldehydes, strongly preferring the amino/keto form over the imino/enol tautomer. With cytosine and 1-methylcytosine, unequivocal evidence for ring-chain tautomerism was additionally obtained: intramolecular nucleophilic attack of cytosine N3 to one of the carbonyl carbons results in reversible cyclization to a 4-hydroxy-4H-pyrimido[1,6-a]pyrimidin-6(7H)-one derivative (9b, 10b). In dry methanol the corresponding O-methyl ether (12) was obtained.