Construction of Pyrazolo[1,5-a]pyrimidines and Pyrimido[1,2-b]indazoles with Calcium Carbide as an Alkyne Source

One-step construction of both 5-arylpyrazolo[1,5- a ]pyrimidines and 2-arylpyrimido[1,2- b ]indazoles using inexpensive, abundant and easy-to-handle calcium carbide as a solid alkyne source is depicted.