One‐Pot SNAr/Direct Pd‐Catalyzed CH Arylation Functionalization of Pyrazolo[1, 5‐a]pyrimidine at the C3 and C7 Positions. Issue 29 (10th July 2018) - Loubidi, Mohammed
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 SN Ar amination followed by a Pd‐catalyzed direct CH‐arylation was developed, then a parallel single‐pot SN 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. Abstract : We report in this paper a novel and efficient protocol for the synthesis of a 3, 7‐disubstituted pyrazolo[1, 5‐ a ]pyrimidine library by an SN Ar amination followed by palladium‐catalyzed direct arylation.