Synthesis of pyrimido[1,6-a]quinoxalines via intermolecular trapping of thermally generated acyl(quinoxalin-2-yl)ketenes by Schiff bases

• Svetlana O. Kasatkina,
• Ekaterina E. Stepanova,
• Maksim V. Dmitriev,
• Ivan G. Mokrushin and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2018, 14, 1734–1742, doi:10.3762/bjoc.14.147

• Svetlana O. Kasatkina Ekaterina E. Stepanova Maksim V. Dmitriev Ivan G. Mokrushin Andrey N. Maslivets Department of Chemistry, Perm State University, ul. Bukireva 15, Perm 614990, Russian Federation 10.3762/bjoc.14.147 Abstract Acyl(quinoxalin-2-yl)ketenes generated by thermal decarbonylation of

• 3-acylpyrrolo[1,2-a]quinoxaline-1,2,4(5H)-triones react regioselectively with Schiff bases under solvent-free conditions to form pyrimido[1,6-a]quinoxaline derivatives in good yields. Keywords: acyl(quinoxalin-2-yl)ketenes; cycloaddition; pyrimido[1,6-a]quinoxalines; Schiff bases; thermolysis

• ][37][38][39][40][41][42][43][44][45][46]. The analysis helped us to disclose a tempting but challenging methodology, which has the potential to be extended for the synthesis of the desired heterocyclic system, via intermolecular trapping of thermally generated acyl(quinoxalin-2-yl)ketenes [20][21][23