In the search of new leads towards potent antiviral agents 2,3-disubstituted quinazoline derivatives were synthesized and tested for their antiviral activity. Anthranilic acid (1) on treatment with an aromatic acid chloride in pyridine gives 2-aryl-4-oxo-3H-benzoxazines (2) which in turn reacts with p-amino benzoic acid (PABA) to afford 2-aryl-3-p-carboxylatophenyl-4-oxo-3H-quinazolines (3). The compound 3 further reacts with amido alcohols in the presence of conc. H2SO4 resulting 3-[benzoic acid-(3-phthalimidomethyl/3-ethyl-3H-2-phenyl-4-oxo-quinazolinyl/1-ethyl-7-hydroxy-4-methyl-2-oxo-quinolinyl)]-2-aryl-3H-quinazoline-4-ones (4). The resulting compounds 4a-f have been evaluated for their in vitro and in vivo antiviral activity against JEV and HSV type-I. The synthesized compounds were characterized through their physical and chemical analysis. The obtained results can be used as the key step for the building of novel chemical entities with interesting antiviral activity compare with the standard drugs.
Catalytic aza-Wittig Reaction of Acid Anhydride for the Synthesis of 4<i>H</i>-Benzo[<i>d</i>][1,3]oxazin-4-ones and 4-Benzylidene-2-aryloxazol-5(4<i>H</i>)-ones
copper-catalyzed reduction of phosphine oxide was used and found effective for this transformation. Additionally, the one-pot catalyticaza-Wittig reaction of carboxylic acids was achieved. Furthermore, NMR experiments and Hammett plot recorded the process of catalyticaza-Wittig reaction of anhydride, which provides direct proof that the copper-catalyzed reduction of waste phosphine oxide is the key step
与醛,酮,酰胺和酯的aza-Wittig反应相比,酸酐的aza-Wittig反应总是被忽略,这应该是Wittig反应的重要组成部分。在这里,酸酐的aza-Wittig反应和酸酐的aza-Wittig催化反应均以高收率开发,这为合成4 H-苯并[ d ] [1,3]恶嗪-4-酮和4-亚苄基-2-芳基恶唑-5(4 H)-那些。使用了铜催化的氧化膦还原的策略,发现该策略对这种转化有效。另外,实现了羧酸的一锅催化的氮杂-维蒂希反应。此外,NMR实验和Hammett曲线记录了酸酐的催化氮杂-维蒂希反应过程,这直接证明了铜催化的废氧化膦的还原是该转化过程中的关键步骤。
Synthesis of 2-substituted-4H-3,1-benzoxazin-4-ones
作者:D. I. Bain、R. K. Smalley
DOI:10.1039/j39680001593
日期:——
yield. With 1 mol. of benzoyl chloride, however, a mixture of benzoxazinone and N-benzoylanthranilic acid was obtained. The mechanism of the reaction has been investigated and various 2-substituted-4H-3,1-benzoxazin-4-ones have been prepared and their u.v. spectra recorded.
邻氨基苯甲酸(1摩尔)在吡啶溶液中与苯甲酰氯(2摩尔)反应,以高收率得到2-苯基-4 H -3,1-苯并恶嗪-4-酮。与1摩尔。然而,得到了苯甲酰氯的苯并恶嗪酮和N-苯并氰基邻氨基苯甲酸的混合物。已经研究了反应的机理,并制备了各种2-取代的-4 H -3,1-苯并恶嗪-4-酮,并记录了它们的uv光谱。