A series of novel substituted isoquinolones have been synthesised. This has been achieved by two routes, either Curtius rearrangment of cinnamic acids or via an isoquinoline N-oxide. (C) 2002 Elsevier Science Ltd. All rights reserved.
Synthesis and evaluation of ureido and vinylureidopenicillins as inhibitors of intraruminal lactic acid production
摘要:
A series of 14 vinylureidopenicillins and a series of 9 ureidopenicillins were prepared by reaction of 6-aminopenicillanic acid with vinyl isocyanates and isocyanates. These compounds were evaluated for their potential to protect ruminants against lactic acidosis. The compounds were tested for inhibition of in vitro ruminal lactic and propionic acid production, and six compounds inhibited lactic acid production to less than 10% of control at doses of 0.31 microgram/mL or lower, whereas they did not inhibit propionic acid production at doses greater than 10 micrograms/mL. The most active compounds also were screened for general antibacterial activity and were found to be weakly active against Gram-positive bacteria. The structure--activity relationships are discussed for both series. Triethylammonium 6-[3[2-(4-tert-butylphenyl)vinyl]ureido]penicillanate (4) was chosen for evaluation as an inhibitor of intraruminal lactic acidosis in vivo.
Chiral phosphoric acid catalyzed enantioselective annulation of acyclic enecarbamates to in situ-generated ortho-quinone methides
作者:Chandan Gharui、Shreya Singh、Subhas Chandra Pan
DOI:10.1039/c7ob01766a
日期:——
The first organocatalytic asymmetric reaction of acyclic enecarbamates with o-quinone methides is disclosed. BINOL-based phosphoric acid catalysts were found to be suitable for the annulation reaction. With 10 mol% of the TRIP catalyst, high yields as well as excellent diastereo- and enantioselectivities are achieved for a variety of 2,3,4-trisubstituted chroman products.
Synthesis of Acyl Azides Using the Vilsmeier Complex
作者:Radhakrishnan Sridhar、Paramasivan T. Perumal
DOI:10.1081/scc-120015815
日期:2003.1.4
Abstract A facile synthesis of substituted cinnamoyl and benzoyl azides starting from their respective acids using DMF and POCl3 in the presence of sodium azide is reported.
Abstract Thermal-induced dimerization cyclization of ethyl N-(styrylcarbamoyl)acetate derivatives has been investigated, leading to 4-hydroxy-2(1H)-pyridone-3-carboxamide derivatives with good yields in diphenyl ether on 200–210 °C. Ethyl N-(styrylcarbamoyl)acetate derivatives readily provided the intermolecular cyclization products 4-hydroxy-2(1H)-pyridone-3-carboxylates on reflux in xylene. In addition
摘要 已经研究了 N-(苯乙烯基氨基甲酰基)乙酸乙酯衍生物的热诱导二聚环化,导致 4-羟基-2(1H)-吡啶酮-3-甲酰胺衍生物在二苯醚中在 200-210 °C 下具有良好的产率。N-(苯乙烯基氨基甲酰基)乙酸乙酯衍生物在二甲苯中回流时容易提供分子间环化产物4-羟基-2(1H)-吡啶酮-3-羧酸酯。此外,还制备了几种相关的 3-acetyl-4-hydroxy-5-phenylpyridin-2(1H)-ones。它提供了 4-羟基-2(1H)-吡啶酮-3-甲酰胺衍生物的有效制备方法。图形概要
Youssef, Abdel-Hamid A.; Sharaf, Saber M.; Abdel-Baki, Samy A., Journal fur praktische Chemie (Leipzig 1954), 1982, vol. 324, # 3, p. 491 - 497
作者:Youssef, Abdel-Hamid A.、Sharaf, Saber M.、Abdel-Baki, Samy A.