The structure of 2,4,6-tris[di(tert-butoxycarbonyl)methylidene]-hexahydro-1,3,5-triazine

Abstract

The structure of 2,4,6 tris[di(tert butoxycarbonyl)methylidene]hexahydro 1,3,5 triazine was studied by quantum chemistry, NMR and IR spectroscopy, and X ray diffraction. This compound exists exclusively in the hexahydro 1,3,5 triazine form both in solution and in the solid phase, although due to the loss of the aromatization energy, this structure should be less stable than a 1,3,5 triazine structure. The formation of strong intramolecular hydrogen bonds confirmed by NMR and IR spectroscopy and X ray diffraction data may be a main reason for stabilization of the hexahydro 1,3,5 triazine isomer.

Thermodynamic stability of 2,4,6-tris(nitromethyl)-1,3,5-triazine: an experimental and theoretical study

“…The spectrum also exhibits signals in the region δ 14-15, which probably correspond to NH groups and/or OH groups at the double bond. 1 The appearence of these signals is an indication of tautomeric equilibrium rather than a chemical reaction of 1 with the solvent because after evaporation of DMSO and dissolu tion of the residue in acetonitrile d 3 the initial shape of the signal of compound 1 is almost fully recovered. Storage of the sample in DMSO over a period of a month resulted in establishment of an equilibrium between several major tautomeric forms of 1.…”

“…A possible reason for stabilization of hexahydro 1,3,5 triazine can be the presence of intramolecular hydrogen bonds. 1 Such bonds are also formed in acyclic 1 amino and 1,1 diamino ethylenes containing one or two acceptor groups, such as COOR, COR, CN, NO 2 at the C(2) atom. 2- 6 The existence of cyclic and acyclic derivatives of 1,1 diamino 2 nitroethylene, 1,1 diamino 2,2 dinitro ethylene, and 1 amino 2 nitroethylene mainly in the ethylene form stabilized by intramolecular hydrogen bond (Scheme 1) was discussed.…”