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.

中文翻译：

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HCl催化的Friedel-Crafts烷基化反应有效合成6-苄基-2-芳基噻吩并[2,3-d]嘧啶-4（3H）-酮

乙醛不仅可以随后与2-氨基噻吩-3-羧酰胺进行缩合和环化以构建一个嘧啶环，而且还可以与噻吩部分进行Friedel-Crafts烷基化反应，从而产生意想不到的6-苄基-2-芳基噻吩并[2,3- d ]嘧啶-4（3 H）-浓HCl催化收率高。