Synthesis and tautomerization of hydroxylated isoflavones bearing heterocyclic hemi-aminals. Issue 4 (21st November 2014)

• Record Type: Journal Article
• Authors: Frasinyuk, Mykhaylo S.; Bondarenko, Svitlana P.; Khilya, Volodymyr P.; Liu, Chunming; Watt, David S.; Sviripa, Vitaliy M.
• Is Part Of: Organic & biomolecular chemistry. Volume 13:Issue 4(2015)
• Page Start: 1053
• Page End: 1067
• Publication Date: 2014-11-21
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c4ob02137a
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : Aminomethylation of 7-hydroxy isoflavones with C2 –C5 ω-aminoalcohols led to tautomers4 and5 that were interconverted as confirmed by NMR studies. Abstract : The aminomethylation of hydroxylated isoflavones with 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, and 5-amino-1-pentanol in the presence of excess formaldehyde led principally to 9-(2-hydroalkyl)-9, 10-dihydro-4 H, 8 H -chromeno[8, 7- e ][1, 3]-oxazin-4-ones4 and/or the tautomeric 7-hydroxy-8-(1, 3-oxazepan-3-ylmethyl)-4 H -chromen-4-ones5 . The ratio of these tautomers was dependent on solvent polarity, electronic effects of aryl substituents in the isoflavone and the structure of the amino alcohol. NMR studies confirmed the interconversion of tautomeric forms.