Synthesis and structure of regioisomeric amino enones containing 2-pyridyl and CF3 substituents

• Published in: Russian chemical bulletin Vol. 69; no. 12; pp. 2355 - 2362
• Main Authors: Slepukhin, P. A., Boltacheva, N. S., Pervova, M. G., Filyakova, V. I., Charushin, V. N.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2020
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Full Articles; Inorganic Chemistry; Organic Chemistry; lithium -1,1,1-trifluoro-4-oxo-4-(2-pyridyl)but-2-en-2-olate; 4-amino-1,1,1-trifluoro-4-(2-pyridyl)but-3-en-2-one; C NMR spectroscopy; F, and; 3-amino-4,4,4-trifluoro-1-(2-pyridyl)but-2-en-1-one; amino enones; chromatography-mass spectrometry; H; crystal structure; X-ray diffraction; organofluorine compounds
• DOI: 10.1007/s11172-020-3030-1
• ISSN: 1066-5285

Regioisomeric amino enones ( Z )-4-amino-1,1,1-trifluoro-4-(2-pyridyl)but-3-en-2-one and ( Z )-3-amino-4,4,4-trifluoro-1-(2-pyridyl)but-2-en-1-one were synthesized by the reaction of lithium ( Z )-1,1,1-trifluoro-4-oxo-4-(2-pyridyl)but-2-en-2-olate with ammonium acetate in glacial AcOH. A comparative study of physicochemical properties and the crystal structures showed that the molecules of these new compounds are planar (except for two fluorine atoms) with an U-shaped configuration of the keto enamine moiety. A change in the position of the amino group with respect to the CF 3 substituent leads to significant changes in the electron density distribution and the C-C bond lengths in the keto enamine moiety and also in the character of intermolecular hydrogen bonds responsible for the crystal packing mode of regioisomeric amino enones.