An efficient synthesis of 6‐benzyl‐2‐arylthieno[2,3‐d]pyrimidin‐4(3H)‐ones catalyzed by HCl involving a Friedel‐Crafts alkylation reaction

Abstract

Aldehyde could undergo not only the subsequent condensation and cyclization with 2‐aminothiophene‐3‐carboxamide to build a pyrimidine ring, but also a Friedel‐Crafts alkylation reaction with thiophene moiety to give unexpected 6‐benzyl‐2‐arylthieno[2,3‐d]pyrimidin‐4(3H)‐ ones in good yields catalyzed by concentrated HCl.