In this report, we describe a new method for the synthesis of densely functionalized 2(1H)-pyrazinones. Treatment of mesoionic 1,3-oxazolium-5-olates with carbanions derived from activated methylene isocyanides (p-toluenesulfonylmethyl isocyanide (TosMIC) and ethyl isocyanoacetate) causes a novel ring transformation affording 2(1H)-pyrazinones in moderate to high yields. The cytotoxicity and antibacterial
Regioselective reaction of mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates and phenylhydrazine: Synthesis of trifluoromethyl substituted pyrazole and 1,2,4-triazine derivatives
6-Trifluoromethyl-1,2,4-triazines (2), 3-trifluoromethyl-5-pyrazolones (3), or 5-trifluoromethyl-3-hydroxypyrazoles (4) are selectively btained in good yields through the regioselective attack of phenylhydrazine on mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates (1), depending on the nature of the reaction solvent and temperature.
Facile Synthesis of Imidazo[1,5-a]pyrazin-8(7H)-ones from Mesoionic 1,3-Oxazolium-5-olates via a Multistep One-Pot Transformation
作者:Masami Kawase、Ryosuke Saijo、Hidemitsu Uno
DOI:10.3987/com-16-13551
日期:——
A novel one-pot conversion of mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates into imidazo[1,5-a]pyrazin-8(7.H)-ones by the reaction with TosMIC is described. The structure of the product was determined by single-crystal X-ray analysis.