One‐Pot S_NAr/Direct Pd‐Catalyzed CH Arylation Functionalization of Pyrazolo[1,5‐<i>a</i>]pyrimidine at the C3 and C7 Positions

Abstract

An efficient and original synthesis of various 3,7‐substituted pyrazolo[1,5‐ a ]pyrimidines is reported. First, a two‐step process by an S N Ar amination followed by a Pd‐catalyzed direct CH‐arylation was developed, then a parallel single‐pot S N Ar amination/CH arylation sequence was performed starting from 7‐chloro‐5‐methyl‐2‐phenylpyrazolo[1,5‐ a ]pyrimidine to obtain highly functionalized products with good yields.