High-speed microwave-promoted hetero-Diels-Alder reactions of 2(1H)-pyrazinones in ionic liquid doped solvents.
Inter- and intramolecular hetero-Diels-Alder reactions in a series of functionalized 2(1H)-pyrazinones were investigated under controlled microwave irradiation. The cycloaddition reactions were efficiently performed in sealed tubes, utilizing either a combination of 1,2-dichloroethane and a thermally stable ionic liquid, or 1,2-dichlorobenzene as reaction medium. In all cases, a significant rate-enhancement using microwave flash heating as compared to thermal heating was observed.
Van Der Eycken
Erik
E
Laboratory for Organic Synthesis, Katholieke Universiteit Leuven, Celestijnenlaan 200F, B-3001 Heverlee, Belgium. vandereycken@chem.kuleuven.ac.be
Appukkuttan
Prasad
P
De Borggraeve
Wim
W
Dehaen
Wim
W
Dallinger
Doris
D
Kappe
C Oliver
CO