Synthesis of some novel pyrazolo[1,5-<i>a</i>]quinazolines and their fused derivatives

New pyrazolo[1,5-<i>a</i>]quinazoline-3-carbonitriles <b>4a,b</b> were obtained via cyclocondensation of 5-amino-3-cyanomethyl-1<i>H</i>-pyrazole-4-carbonitrile (<b>1</b>) with enaminones of 1,3-cyclohexanedione derivatives <b>2a,b</b> in refluxing glacial acetic acid. Condensation of compounds <b>4a,b</b> with various aromatic aldehydes furnished the corresponding arylidene derivatives <b>6a–j</b>. On the other hand, condensation of <b>4a,b</b> with o-hydroxybenzaldehydes yielded the polyheterocyclic compounds <b>10a–h</b>. Coupling of compounds <b>4a,b</b> with aryldiazonium chlorides led to formation of 2-arylhydrazono derivatives <b>12a–h</b>. Also, reaction of compounds <b>4a,b</b> with phenyl isothiocyanate, followed by addition of ethyl chloroacetate and chloroacetonitrile, afforded the polyheterocyclic compounds based on pyrazolo[1,5-<i>a</i>]quinazoline core. The reaction of compounds <b>4a,b</b> with phenyl isothiocyanate and elemental sulfur gave the thiazole-2-thione derivatives <b>25a,b</b>. The reaction of enamines of compounds <b>4a,b</b> with each of hydrazine hydrate and guanidine hydrochloride afforded pyrazolo[4″,3″:5′,6′]pyrido[4′,3′:3,4]pyrazolo[1,5-<i>a</i>]quinazolin-8-ones <b>30a,b</b> and pyrimido[5″,4″:5′,6′]pyrido[4′,3′:3,4]pyrazolo[1,5-<i>a</i>]quinazolin-9(10H)-ones <b>33a,b</b>, respectively. The structures of all the newly synthesized compounds were elucidated by elemental analyses and spectral data. The plausible mechanisms have been postulated to account for their formation.新型吡唑并[1,5-a]喹唑啉-3-甲腈（pyrazolo[1,5-a]quinazoline-3-carbonitriles）类化合物4a,b，可由5-氨基-3-氰甲基-1H-吡唑-4-甲腈（5-amino-3-cyanomethyl-1H-pyrazole-4-carbonitrile，化合物1）与1,3-环己二酮衍生的烯胺酮（enaminones of 1,3-cyclohexanedione derivatives，化合物2a,b）在冰乙酸（glacial acetic acid）中回流发生环缩合反应制得。将化合物4a,b与多种芳醛（aromatic aldehydes）进行缩合反应，可得到对应的亚芳基类衍生物6a–j。另一方面，将化合物4a,b与邻羟基苯甲醛（o-hydroxybenzaldehydes）缩合，可得到多杂环类化合物10a–h。将化合物4a,b与芳基重氮氯盐（aryldiazonium chlorides）进行偶联反应，可得到2-芳基腙类衍生物12a–h。此外，将化合物4a,b与异硫氰酸苯酯（phenyl isothiocyanate）反应后，依次加入氯乙酸乙酯与氯乙腈，可得到以吡唑并[1,5-a]喹唑啉为母核的多杂环类化合物。将化合物4a,b与异硫氰酸苯酯及单质硫（elemental sulfur）反应，可得到噻唑-2-硫酮（thiazole-2-thione）类衍生物25a,b。将化合物4a,b的烯胺分别与水合肼（hydrazine hydrate）、盐酸胍（guanidine hydrochloride）反应，可分别得到吡唑并[4″,3″:5′,6′]吡啶并[4′,3′:3,4]吡唑并[1,5-a]喹唑啉-8-酮（pyrazolo[4″,3″:5′,6′]pyrido[4′,3′:3,4]pyrazolo[1,5-a]quinazolin-8-ones）类化合物30a,b，以及嘧啶并[5″,4″:5′,6′]吡啶并[4′,3′:3,4]吡唑并[1,5-a]喹唑啉-9(10H)-酮（pyrimido[5″,4″:5′,6′]pyrido[4′,3′:3,4]pyrazolo[1,5-a]quinazolin-9(10H)-ones）类化合物33a,b。所有新合成化合物的结构均通过元素分析与光谱数据进行了确证，并对其可能的形成机理进行了推测。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于新型吡唑并[1,5-a]喹唑啉及其融合衍生物的化学合成研究，包含实验合成文档和光谱数据文档，总大小5.87 MB。数据集发布于2017年，使用CC BY 4.0许可证，提供详细的合成方法、反应机制和化合物结构分析，适用于生物化学、药理学等领域的科研人员。