An efficient one-pot, three-component synthesis of highly substituted bicyclic pyridines containing a ring-junction nitrogen, starting from simple and readily available materials, is described. Cyclocondensation of heterocyclic ketene aminals (HKAs), triethoxymethane, and active methylene compounds by refluxing under solvent-free and catalyst-free conditions, provided bicyclic pyridines in excellent yields. [ABSTRACT FROM AUTHOR]
Pereiro, A. B., Tojo, E., Rodríguez, A., Canosa, J., and TojoThis paper is dedicated to the memory of Prof. José Tojo who recently passed away., J.
Abstract
1-Hexyl-3-methylimidazolium hexafluorophosphate (HMImPF6) is suitable for use as the solvent in the petrochemical extraction process for the removal of heptane from its azeotropic mixture with ethanol. The experimental determination of the liquid–liquid equilibrium (LLE) for the ternary system heptane ethanol HMImPF6at 298.15 K was carried out. The solute distribution ratio and the selectivity of the HMImPF6have been determined from the tie-line data. A comparative study has been made in terms of selectivity and solute distribution data with other ionic liquids. The NRTL equation was verified to accurately correlate the experimental data.