Affordable Access

Solid-state tautomeric structure and invariom refinement of a novel and potent HIV integrase inhibitor

  • Chemistry
  • Pharmaceutical


The conformation and tautomeric structure of (Z)-4-[5-(2,6-difluoro­benzyl)-1-(2-fluoro­benzyl)-2-oxo-1,2-dihydro­pyridin-3-yl]-4-hy­droxy-2-oxo-N-(2-oxopyrrolidin-1-yl)but-3-enamide, C27H22F3N3O5, in the solid state has been resolved by single-crystal X-ray crystallography. The electron distribution in the mol­ecule was evaluated by refinements with invarioms, aspherical scattering factors by the method of Dittrich et al. [Acta Cryst. (2005), A61, 314–320] that are based on the Hansen–Coppens multipole model [Hansen & Coppens (1978 ▶). Acta Cryst. A34, 909–921]. The β-diketo portion of the mol­ecule exists in the enol form. The enol –OH hydrogen forms a strong asymmetric hydrogen bond with the carbonyl O atom on the β-C atom of the chain. Weak intra­molecular hydrogen bonds exist between the weakly acidic α-CH hydrogen of the keto–enol group and the pyridinone carbonyl O atom, and also between the hydrazine N—H group and the carbonyl group in the β-position from the hydrazine N—H group. The electrostatic properties of the mol­ecule were derived from the mol­ecular charge density. The mol­ecule is in a lengthened conformation and the rings of the two benzyl groups are nearly orthogonal. Results from a high-field 1H and 13C NMR correlation spectroscopy study confirm that the same tautomer exists in solution as in the solid state.

There are no comments yet on this publication. Be the first to share your thoughts.