Search for "1,2,4-triazolo[1,5-a]pyrimidines" in Full Text gives 2 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2017, 13, 2535–2548, doi:10.3762/bjoc.13.250
Beilstein J. Org. Chem. 2017, 13, 2396–2407, doi:10.3762/bjoc.13.237