Abstract Interaction of methyl 3-ethoxy-2-(2,5-dichloro-3-thenoyl)acrylate (I) with 3-aminopyrazole and 3-amino-1,2,4-triazole generated the respective pyrazolo[1,5-α]pyrimidine (4) and triazolo[1,5-α]pyrimidine (7). The formation of 4 entails selective and consecutive displacement of the 3-ethoxy and methoxy (ester) anions in I by 3-NH2 and 1-NH of 3-aminopyrazole. On the other hand, the formation of 7 implies selective displacement of 3-ethoxy in I by the ring-NH followed by cyclocondensation involving the keto group in I and 3-NH2 of aminotriazole. This latter selective displacement sequence is also followed by 3-amino-5-hydroxypyrazole in its reaction with I. The structures of the new compounds are supported by microanalytical and spectral data.

中文翻译：

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甲基 3'-杂芳基氨基-2'-(2,5-二氯噻吩-3-羰基)丙烯酸酯的选择性环化模式。模型（噻吩基）吡唑并和三唑并[1,5-α]嘧啶的合成

摘要 3-乙氧基-2-(2,5-二氯-3-thenoyl) 丙烯酸甲酯 (I) 与 3-氨基吡唑和 3-氨基-1,2,4-三唑的相互作用生成各自的吡唑并[1,5- α]嘧啶 (4) 和三唑并 [1,5-α] 嘧啶 (7)。4 的形成需要 3-氨基吡唑的 3-NH2 和 1-NH 选择性地连续置换 I 中的 3-乙氧基和甲氧基（酯）阴离子。另一方面，7 的形成意味着 I 中的 3-乙氧基被环-NH 选择性置换，然后涉及 I 中的酮基和氨基三唑的 3-NH2 的环缩合。后者的选择性置换序列也跟随着 3-氨基-5-羟基吡唑与 I 的反应。新化合物的结构得到了微量分析和光谱数据的支持。