Abstract New pyrazolothienopyrimidines were synthesized. The key intermediate 4-aminothieno[2,3-c]pyrazole-5-carbonitrile 1 was converted to the chloroacetyl amino derivative 2 followed by nucleophilic substitution and Dimorth rearrangement upon treatment with nitrogen nucleophiles to give the pyrimidinones 3a-c. Treatment of 3a with formaldehyde and with triethyl orthoformate afforded the respective tetracyclic derivatives 4 and 5. Condensation of the amino group in the o-aminocarbonitrile 1 with triethyl orthoformate followed by cycloaddition reaction with hydrazine led to the formation of pyrazolothienopyrimidine 8. Compound 8 was used as a synthetic precursor to heterocyclic compounds comprised of pyrazole, triazole, triazine, and triazepine derivatives.

中文翻译：

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吡唑并[4',3':4,5]噻吩并[3,2-d]嘧啶和相关杂环的高效合成、反应和光谱表征

摘要 合成了新型吡唑并噻吩并嘧啶类化合物。关键中间体 4-氨基噻吩并 [2,3-c] 吡唑-5-甲腈 1 被转化为氯乙酰氨基衍生物 2，然后在用氮亲核试剂处理后进行亲核取代和 Dimorth 重排，得到嘧啶酮 3a-c。用甲醛和原甲酸三乙酯处理 3a 得到各自的四环衍生物 4 和 5。邻氨基甲腈 1 中的氨基与原甲酸三乙酯缩合，然后与肼进行环加成反应导致形成吡唑并噻吩并嘧啶 8。使用化合物 8作为由吡唑、三唑、三嗪和三氮杂衍生物组成的杂环化合物的合成前体。