Synthesis of 4-unsubstituted dihydropyrimidines. Nucleophilic substitution at position-2 of dihydropyrimidines

Hidetsura Cho, Yoshio Nishimura, Yoshizumi Yasui, Satoshi Kobayashi, Shin Ichiro Yoshida, Eunsang Kwona, Masahiko Yamaguchi

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


Synthesis of novel 4-unsubstituted dihydropyrimidines (DPs) was performed. Subsequently, a variety of 4-unsubstituted 1,4(3,4)-DPs with amino moieties at position-2 were obtained in excellent yields by activation of position-2 owing to regioselective alkoxycarbonylation at position-3 of the DP skeleton. 3-Oxo-2-phenyl-2,3,5,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrimidine was obtained using phenylhydrazine instead of amines. Individual tautomers of 1,4(3,4)-DP were observed in the 1H NMR spectra of one derivative depending on temperature and concentration. On the other hand, only 1,4-DP was found in the solid state by single-crystal X-ray crystallography.

Original languageEnglish
Pages (from-to)2661-2669
Number of pages9
Issue number14
Publication statusPublished - 2011 Apr 8
Externally publishedYes


  • 2,3,5,8-Tetrahydro[1,2,4]triazolo[4,3-a]
  • Dihydropyrimidine
  • Individual tautomer
  • Nucleophilic substitution
  • Pyrimidine
  • Tautomerism
  • X-ray diffraction

ASJC Scopus subject areas

  • Biochemistry
  • Drug Discovery
  • Organic Chemistry


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