Regioselective C3-halogenations of N-(pyrazolo[1,5-a]pyrimidin-7-yl) acetamides

Regioselective C3-halogenations of N-(pyrazolo [1,5-a]pyrimidin-7-yl)acetamide with N-halosuccinimides (NBS or NCS) have been achieved. A diverse array of C3-halogenated products are provided in high yields with excellent regioselectivity. The practicability of this approach is highlighted by simple condition reactions, broad substrate scope, gram-scale reaction. Moreover, further derivatization reactions demonstrated the versatility of the products.