85870-82-2Relevant academic research and scientific papers
SYNTHESIS AND PROPERTIES OF 2,2'-PYRROMETHENE-5(1H)-ONE ANALOGUES: THE FURAN, THIOPHENE, BENZENE, 4-METHOXYBENZENE, 2-PYRIDINE AND 4-PYRIDINE ANALOGUES
Groot, J. A. de,Jansen, H.,Fokkens, R.,Lugtenburg, J.
, p. 114 - 118 (2007/10/02)
Condensation of furfural, thiophene-2-carboxaldehyde, benzaldehyde, 4-methoxy-benzaldehyde, pyridine-2-carboxaldehyde and pyridine-4-carboxaldehyde with 3,4-dimethyl-3-pyrrolin-2-one leads to the Z-2,2'-pyrromethene-5(1H)-one analogues.Following irradiation with light, the E forms have been isolated and characterized.Complete thermal E -> Z isomerisation is observed upon heating in basic methanol.On irradiation in non hydrogen-donating solvents the analogues 3a, 3b and 3e show very little or no photoisomerisation due to the intramolecular hydrogen bond.Condensation of these aldehydes with 1,3,4-trimethyl-3-pyrrolin-2-one gives mixtures of the corresponding Z- and E-2,2'-pyrromethene-5(1H)-one analogues.The Z and E forms both isomerise thermally upon heating in basic methanol to give the same equilibrium state as is observed during the synthesis.Upon irradiation with light, the compounds similarly undergo Z-E isomerisation.
