174469-59-1Relevant articles and documents
Highly facile and regio-selective synthesis of pyrazolo[1,5-a]pyrimidines via reactions of 1,2-allenic ketones with aminopyrazoles
Zhang, Xinying,Song, Yunping,Gao, Lin,Guo, Xiaojie,Fan, Xuesen
supporting information, p. 2099 - 2107 (2014/03/21)
An efficient procedure for the syntheses of pyrazolo[1,5-a]pyrimidines through reactions of 1,2-allenic ketones with aminopyrazoles under extremely mild conditions without using any catalyst or promoter has been developed. The reactions showed excellent regio-selectivity with all the allenic ketone substrates except for those bearing an alkyl group at the internal position of the allene moiety. The reason behind this regio-selectivity dissimilarity has been explored with the aid of the B3LYP/6-31G* level of density functional theory. Moreover, this novel procedure has been successfully applied in the preparation of nucleoside-pyrazolo[1,5-a]pyrimidine chimeras with potent antiviral activities.
Chemical and Electrochemical Reduction of some Pyrazolopyrimidines
Bellec, Christian,Lhommet, Gerard
, p. 1793 - 1800 (2007/10/03)
Various pyrazolopyrimidines 1 are prepared by two different ways.Their chemical reduction by sodium borohydride leads generally to 4,5,6,7-tetrahydro compounds 3, while lithium aluminum hydride yields 4,7-dihydro derivatives 2 at room temperature, and 3 in refluxing tetrahydrofuran.A complex mixture of oxidizable hydrodimers is obtained by electrochemical reduction.An electroreduction at a more negative potential also gives 4,7-dihydro compounds 2.A new 4,5-dihydropyrazolopyrimidine has been obtained by condensation of 5-amino-3-methyl-1H-pyrazole with acetophenone.
