A novel tert-amino effect based approach to 1,2,3,4-tetrahydroquinoline-2-spirocycloalkanes

An interaction of 2-[cyclohexyl(methyl)amino]benzaldehydes with substituted acetonitriles X-CH₂CN (X=CN, Tos, hetaryl) was found to yield 1-methyl-1,2,3,4-tetrahydrospiro(quinoline-2,1′-cyclohexane)-3-carbonitriles. The corresponding spiroquinoline-2,1′-cyclopentane analogues were obtained similarly starting from 2-[cyclopentyl(methyl)amino]benzaldehydes. The reaction was assumed to proceed via initial Knoevenagel condensation and further ring closure of the formed adduct according to the tert-amino effect mechanism. The structure of the prepared compounds was confirmed unambiguously by X-ray crystallographic study.

Tverdokhlebov A. V.; Gorulya A. P.; Tolmachev A. A.; Kostyuk A. N.; Chernega A. N.; Rusanov E. B.
Tetrahedron 2006, 62 (39), 9146-9152
DOI: 10.1016/j.tet.2006.07.042