Isocyanate acting as a carbonyl precursor: Pyridyl group-assisted formation of 4H-pyrido[1,2-a]pyrimidin-4-ones from ketimines and isocyanates

Yoichiro Kuninobu, Shuhei Nishimura, Kazuhiko Takai

Research output: Contribution to journalArticle

9 Citations (Scopus)


By the reactions of ketimines bearing a pyridyl or a picolyl group on a nitrogen atom of the imine moiety with tosylisocyanate, 4H-pyrido[1,2-a] pyrimidin-4-one derivatives could be obtained in quantitative yields. In these reactions, tosylisocyanate acts as a carbonyl precursor. The pyridyl or picolyl group is a key functional group because it is not only the constituent structure of the 4H-pyrido[1,2-a]pyrimidin-4-one framework but also the promoter of the formation of a ketene intermediate.

Original languageEnglish
Pages (from-to)203-205
Number of pages3
JournalOrganic and Biomolecular Chemistry
Issue number2
Publication statusPublished - 2006


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Chemistry(all)

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