Synthesis and Characterization of Novel Quinazoline-Substituted 1,3,4-Thiadiazolium-5-thiolates

Abstract

Novel 3-[4-(6-bromo-4-oxo-2-phenylquinazolin-3(4H)-yl)benzoyl]-2-substituted-1,3,4-thiazolium-5-thiolate 7(a–j) and 3-{4-[(6-bromo-2-phenylquinazolin-4-yl)amino] benzoyl}-2-substituted-1,3,4-thiadiazolium-5-thiolate 12(a–j) were synthesized from 6-bromo-2-phenyl-4H-3,1-benzoxazin-4-one (1). The structures of the newly synthesized compounds were confirmed by spectral data and elemental analysis.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT     

Spectral Characterization of Novel 3-Phenyl-2-Substituted Quinazoline and Fused Quinazoline Derivatives

3-phenyl-2-thioxo-quinazolin-4(3H)one 1 was utilized for the construction of some novel 2-substituted quinazolin-4(3H)one derivatives through the formation of 2-hydrazinyl quinazolinone, which was used as the key starting material for the synthesis of 2-heteryl quinazolines via the reaction with one carbon donors, β-diketones and β-ketoester. Infrared, ¹H NMR, and mass spectra of the synthesized compounds were discussed. Some of them showed promising anti-inflammatory activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

N-[3-(4-喹唑啉基)氨基-1H-吡唑-4-甲酰基]醛腙类衍生物的合成及抗菌活性研究

以4-氯喹唑啉、3-氨基-4-吡唑甲酸乙酯和芳醛为原料,合成了13个新型的N-[3-(4-喹唑啉基)氨基-1H-吡唑-4-甲酰基]醛腙类化合物,通过IR,1H NMR,13C NMR和元素分析对其结构进行了确认.初步生物活性测试结果表明,在50 μg/mL浓度下,化合物5d对小麦赤霉菌和苹果腐烂菌的抑制率与对照药剂嗯霉灵相当;化合物5k对小麦赤霉菌的抑制率则高于噁霉灵.     

Discovery of Quinazoline-2,4(1H,3H)-Dione Derivatives as Potential Antibacterial Agent: Design,Synthesis, and Their Antibacterial Activity

In this paper, we report on the design and synthesis of a novel series of quinazoline-2,4(1H,3H)-dione derivatives as fluoroquinolone-like inhibitors of bacterial gyrase and DNA topoisomerase IV to identify and develop antimicrobial agents to prevent bacterial resistance problems. Their structures were confirmed using spectroscopic analyses (IR, NMR, and EI-MS). The novel quinazoline-2,4(1H,3H)-dione derivatives were evaluated for their antimicrobial activities against Gram-positive and Gram-negative bacterial strains using the Agar well diffusion method to study the antimicrobial activities and compared them with the standard drugs. Most compounds displayed moderate activity. Among the tested compounds, the most promising compounds 13 and 15 provided broad bioactive spectrum against Gram-positive and Gram-negative strains compared to the standard drugs.     

Copper-Catalyzed Acceptorless Dehydrogenative Coupling of 2-Aminoaryl Methanols with Nitriles for Accessing Quinazolines and Quinolines

A copper acetate monohydrate catalyzed simple, effective and economic protocol has been developed for the construction of quinazoline derivatives via acceptorless dehydrogenative coupling of easily available 2-aminoaryl methanols and nitriles. The methodology was also highly effective for the synthesis of medicinally important quinolines analogues. The reactions proceeded in presence of KO^tBu in toluene at 110 °C for 5 h without the requirement of inert condition, external additives and ligands.