A heavy metal- and oxidant-free, one-pot synthesis of pyridines and fused pyridines based on a Lewis acid-catalyzed multicomponent reaction.

The InCl3-catalyzed sequential multicomponent reaction between 2-furfurylamine, ß-dicarbonyl compounds and α,ß-unsaturated aldehydes in ethanol, followed by microwave irradiation in solvent-free conditions, afforded good to excellent yields of highly substituted pyridines, with loss of a 2-furylmethyl side chain. The method was also adapted to the synthesis of quinolones, isoquinolines, phenanthridines and more complex fused pyridine systems.

2,6-Bis(2-chloro-phen-yl)-4-oxo-3,5-diphenyl-heptane-1,1,7,7-tetra-carbo-nitrile.

In the title compound, C(35)H(24)Cl(2)N(4)O, the phenyl rings are oriented almost parallel to each other, making a dihedral angle of 0.6 (2)°, whereas the chloro-phenyl rings are oriented at a dihedral angle of 28.3 (1)°. The crystal structure is stabilized through an extensive series of C-H⋯N, C-H⋯O and C-H⋯Cl inter-actions. One of the C-H⋯N inter-actions generates an R(2) (2)(12) ring motif around a crystallographic inversion centre. C(5), C(10) and C(12) chain motifs are observed in the unit cell through C-H⋯N and C-H⋯Cl inter-actions. During the structure analysis, it was observed that the unit cell contains large accessible voids, which host disordered solvent mol-ecules. This affects the diffraction pattern, mostly at low scattering angles and was corrected with the SQUEEZE program [Spek, A. L. (2009 ▶). Acta Cryst. D65, 148-155].

2-Amino-6-(2,4-dichloro-phen-yl)-4-oxo-3,5-diphenyl-cyclo-hex-2-enecarbonitrile.

In the title compound, C(25)H(18)Cl(2)N(2)O, the cyclo-hexene ring has a sofa conformation. All the substituents in the cyclo-hexene ring, except the cyano group (which is axial) occupy equatorial positions. The crystal structure is stabilized through N-H⋯O hydrogen bonds, forming a chain extending along the b axis and through C-H⋯N and C-H⋯Cl inter-actions. It is remarkable that only one of the amino H atoms is involved in hydrogen bonding.