1. Efficient Construction of Pyrazolo[1,5- a ]pyrimidine Scaffold and its Exploration as a New Heterocyclic Fluorescent Platform.
- Author
-
Hui-Jing Li, Li Liu, Dong Wang, Hua-Zheng Yang, and Yong-Jun Chen
- Subjects
PYRAZOLONES ,PYRIMIDINES ,SULFONES ,FLUORESCENCE spectroscopy - Abstract
Abstract  An efficient, fast and facile pyrazolo[1,5-a]pyrimidine synthetic protocol has been established by the condensation of aminopyrazoles with 1,3-dicarbonyl components in AcOH/H2SO4 system. The pyrazolo[1,5-a]pyrimidine sulfides were selectively oxidized to the sulfones via a temperature-controlled stepwise oxidative fashion. The correlation between the substitution patterns of these pyrazolo[1,5-a]pyrimidines and their fluorescent spectroscopic properties were further examined, which provided the fundamentals for their potential applications in the development of new fluorescent probes. Red-shifts were easily achieved by the incorporation of unsaturated groups at the 5- and 7-positions, which suggested an approach for synthesizing long wavelength pyrazolo[1,5-a]pyrimidine dyes. The fluorescent spectroscopic properties were found to be sensitive to the hydroxy-containing and carbonyl-containing media such as alcohol and acetone, which helps to confirm the promising perspectives of further investigations in this area. [ABSTRACT FROM AUTHOR]
- Published
- 2008