6533b7dcfe1ef96bd12728c9

RESEARCH PRODUCT

N-methyl-1,2-dihydro-2-benzoylmethylenequinolines: configurational dissimilarity with unmethylated congeners

Borys OśmiałowskiRyszard GawineckiErkki KolehmainenMaija Nissinen

subject

Inorganic ChemistryCrystallographyChemistryHydrogen bondStereochemistrySolution stateIntramolecular forceOrganic ChemistryX-ray crystallographyRing (chemistry)SpectroscopyAnalytical Chemistry

description

Abstract Twelve 1-methyl-1,2-dihydro-2-benzoylmethylenequinolines have been synthesized and their structures elucidated by 1 H, 13 C and 15 N NMR, UV–Vis and X-ray methods. The results unambiguously show that these compounds and the corresponding 1,2-dihydro-2-benzoylmethylenequinolines both in crystalline and in solution state are the Z and E isomers, respectively. Comparison of the X-ray structures reveal that ( Z )-1,2-dihydro-2-benzoyl-methylenequinolines are less twisted as compared to their 1-methyl derivatives. This difference is caused by formation of the quasi-aromatic six-membered ring stabilized by an intramolecular hydrogen bond in unmethylated congeners, prevented by N -methylation.

yearjournalcountryeditionlanguage
2000-07-01Journal of Molecular Structure
https://doi.org/10.1016/s0022-2860(00)00424-5