N-(α-Ketoacyl)anthranilicacids were prepared by oxidative ring opening of 3-hydroxyquinoline-2,4(1H,3H)-diones by using paraperiodic acid (H5IO6) or sodium periodate (NaIO4). The optimisation of the reaction conditions is described as well as the utilisation of N-(α-ketoacyl)anthranilicacids in the preparation of anthranilicacid hydrochlorides.
Fischer indolisation of<i>N</i>-(α-ketoacyl)anthranilic acids into 2-(indol-2-carboxamido)benzoic acids and 2-indolyl-3,1-benzoxazin-4-ones and their NMR study
N-(α-ketoacyl)anthranilicacids reacted with phenylhydrazinium chloride in boiling acetic acid to afford 2-(indol-2-carboxamido)benzoic acids in good to excellent yields and 2-indolyl-3,1-benzoxazin-4-ones as by-products. The formation of the latter products could easily be suppressed by a hydrolytic workup. Alternatively, by increasing the reaction temperature and/or time, 2-indolyl-3,1-benzoxazin-4-ones
N-(α-酮酰基)邻氨基苯甲酸与苯肼基氯化物在沸腾的乙酸中反应以良好的产率获得2-(吲哚-2-甲酰胺基)苯甲酸,而2-吲哚基-3,1-苯并恶嗪-4-酮副产品。后者产物的形成可以通过水解后处理容易地抑制。或者,通过提高反应温度和/或时间,可以仅获得2-吲哚基-3,1-苯并恶嗪-4-酮。研究了反应条件的优化以及转化的范围和过程。产物通过1 H,13 C和15 N NMR光谱表征。相应的共振是根据标准1D和梯度选择的2D NMR实验(1 H– 1 H gs -COSY, 1 H– 13 C gs -HSQC, 1 H– 13 C gs -HMBC)和1 H– 15 N gs -HMBC作为测定天然15 N NMR化学位移的实用工具15 N同位素的丰度水平。