Controllable Site-Selective Construction of 2- and 4-Substituted Pyrimido[1,2-b]indazole from 3-Aminoindazoles and
Xiang Liu1, Jinlei Zhou1, Jiatong Lin1
1School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, Zhongshan, 528458, P.R. China.
Abstract:
A straightforward and novel controllable site-selective construction of 2- and 4-substituted pyrimido[1,2-b]indazole from 3-aminoindazoles and ynals has been developed. The high regioselectivity of this reaction could be easily switched by converting different catalytic systems. In this way, a series of 2- and 4-substituted pyrimido[1,2-b]indazole derivatives were obtained in moderate to good yields. In addition, the photophysical properties of compound 3a prepared by the present method were discussed.
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