Syntheses and molecular structures of 2-[1′-N-(alkyl)imino-2′,2′,2′-trifluoroethyl]phenols

Article abstract of DOI:10.1016/0022-1139(96)03441-0

N-(Alkyl)imino derivatives of trifluoroacetyl phenol of the general formula 1,2-C₆H₄[C(=NR)CF₃] [OH] (R = H, 3a; Me, 3b; ⁿPr, 3c; ⁱPr, 3d; CH₂CH₂NH₂, 3e; CH₂CH₂CH₂NH₂, 3f; CH₂CH₂CH₂CH₂NH₂, 3g; CH₂CH₂OH, 3h; CH₂CH₂NMe₂, 3i) were synthesized from 2-trifluoroacetyl phenol and the corresponding primary amines RNH₂. The molecular structures of 3b [monoclinic, P2₁/n, a=6.641(3), b=18.044(8), c=7.716(3) A, β=99.95(4)°], 3d [orthorhombic, P2₁2₁2₁, a=7.784(2), b=9.291(2), c=15.942(4) A] and 3i [monoclinic, P2₁/n, a=8.660(2), b=18.135(2), c=13.300(2) A, β=99.83(2)°] were determined. In the solid state, 3b, 3d and 3i exist exclusively as E isomers with intermolecular hydrogen bridges, whereas according to the 1H and 19F NMR spectra in chloroform solution, compounds 3b, 3c and 3d isomerize to give a mixture of 66% Z and 34% E isomers.