Reaction of 6-methylchromone-3-carbonitrile (1) with acetylacetone under basic conditions afforded 3-acetyl-2,7-dimethyl-5H-chromeno[2,3-b]pyridin-5-one (2) which utilized as a starting substrate. Condensation of compound 2 with a variety of amines and hydrazines produced chromeno[2,3-b]pyridines linked variable compounds in the same molecular frame. Condensation reaction of compound 2 with variable carbon nucleophilic reagents namely; malononitrile, ethyl cyanoacetate, malononitrile dimer, 1H-benzimidazol-2-ylacetonitrile and dimedone produced heteroannulated chromeno[2,3-b]quinolines 18-22. The synthesized compounds were screened in vitro for their antimicrobial activity and revealed remarkable inhibitory effects against the selected microorganisms. Structures of the newly synthesized products have been deduced upon the help of elemental analysis and spectral data (IR, 1H NMR, 13C NMR and mass spectra).

中文翻译：

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某些新型Chromeno [2,3-的构建及生物学评价

在碱性条件下，使6-甲基色酮-3-腈（1 ）与乙酰丙酮反应，得到3-乙酰基-2,7-二甲基-5 H-苯并[2,3 - b ]吡啶-5-酮（2 ），起始基材。化合物2与各种胺和肼的缩合产生了在相同分子框架内连接可变化合物的chromeno [2,3- b ]吡啶。化合物2与可变碳亲核试剂的缩合反应为：丙二腈，氰基乙酸乙酯，丙二腈，1 H-苯并咪唑-2-基乙腈和二甲酮生成异环化的铬诺[2,3- b ]喹啉18- 22 。体外筛选了合成的化合物的抗菌活性，并显示出对所选微生物的显着抑制作用。借助元素分析和光谱数据（IR，1 H NMR，13 C NMR和质谱）推导了新合成产物的结构。