Photochemical reactions of 7-aminocoumarins

Autor: KirpichËnok, M. A., Mel'nikova, L. M., Denisov, L. K., Grandberg, I. I., Akimova, N. P.
Zdroj: Chemistry of Heterocyclic Compounds; January 1989, Vol. 25 Issue: 1 p23-29, 7p
Abstrakt: The photochemical reactions of 4-methyl-7-diethylaminocoumarin with the dimethyl ester of acetylenedicarboxylic acid, diethyl ester of maleic acid, and N-phenylmaleimide in the presence of oxygen and acetophenone give products of the heterocyclization at C(6) and C(8) of coumarin fragment with participation of the diethylamino group. The stereochemical structure of the compounds synthesized was demonstrated using PMR spectroscopy. A mechanism was proposed for this reaction involving the formation of an a-amino radical and its addition to the acetylene or olefin, accompanied by attack on the aromatic ring with subsequent aromatization.
Databáze: Supplemental Index