|
|||||
|
|
Synthesis of 4-unsubstituted dihydropyrimidines. Nucleophilic substitution at position-2 of dihydropyrimidines |
|
| Authors: | Hidetsura Cho Yoshio Nishimura Yoshizumi YasuiSatoshi Kobayashi Shin-ichiro Yoshida Eunsang Kwon Masahiko Yamaguchi |
| Affiliation: | a Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan b Graduate School of Pharmaceutical Sciences, Tohoku University, Japan c WPI Advanced Institute for Materials Research, Tohoku University, Japan d Research and Analytical Center for Giant Molecules, Tohoku University, Japan e Faculty of Pharmacy, Yasuda Women's University, 6-13-1, Yasuhigashi, Asaminami-ku, Hiroshima 731-0153, Japan |
| Abstract: | 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. |
| Keywords: | Dihydropyrimidine Tautomerism Individual tautomer X-ray diffraction Nucleophilic substitution 2,3,5,8-Tetrahydro[1,2,4]triazolo[4,3-a]pyrimidine |
| 本文献已被 ScienceDirect 等数据库收录！ | |