Amongst heterocyclic compounds, quinoline and pyrimidine are advantaged scaffolds that appear as significant assembly motifs for the development of new drug entities. Moreover, quinolinepyrimidine- inspired hybrids have a number of biological characteristics that are known. In addition, many pyrimido[4,5-b]quinoline ring systems (PyQs4,5-b), specifically concerning medicinal chemistry, have been reported over the past decade. The synthesis of (PyQs4,5-b) using barbituric acid, thiobarbituric acid, pyrimidine, and their derivatives is presented in this review. The preparation of PyQs4,5-b was clarified through the following chemical reactions: Friedländer, Vilsmeier-Haack formylation, Hantzsch-like reaction, and one-pot three-component reaction.

中文翻译：

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嘧啶[4,5-b]喹啉衍生物的合成化学及生物活性研究进展（下）

在杂环化合物中，喹啉和嘧啶是有利的支架，它们似乎是新药物实体开发的重要组装基序。此外，喹啉嘧啶启发的杂种具有许多已知的生物学特征。此外，在过去的十年中，已经报道了许多嘧啶并[4,5-b]喹啉环系统（PyQs4,5-b），特别是与药物化学有关的系统。本综述介绍了使用巴比妥酸、硫代巴比妥酸、嘧啶及其衍生物合成 (PyQs4,5-b)。PyQs4,5-b的制备通过以下化学反应阐明：Friedländer、Vilsmeier-Haack甲酰化、类Hantzsch反应和一锅三组分反应。