Syntheses of fluorescent dyes. IX. New 4-hydroxycoumarins, 4-hydroxy-2-quinolones, 2<i>H</i>,5<i>H</i>-Pyrano[3,2-<i>c</i>]benzopyran-2,5-diones and 2<i>H</i>,5<i>H</i>-Pyrano[3,2-<i>c</i>]quinoline-2,5-diones
作者:Andreas Knierzinger、Otto S. Wolfbeis
DOI:10.1002/jhet.5570170204
日期:1980.3
7-Substituted 4-hydroxycoumarins (2a-e) and 4-hydroxy-2-quinolones (2f-i) have been synthesized from the appropriate phenols or anilines and were converted to the enamines 3 using triethoxymethane and aniline. Condensation of 3 with nitriles 4a-h gave substituted 2H,5H-pyrano[3,2-c]benzopyran-2,5-diones (5a-r) or 2H,5H-pyrano[3,2-c]quinoline-2,5-diones (5s-x), which exhibit both spontaneous and stimulated
由适当的酚或苯胺合成了7位取代的4-羟基香豆素(2a-e)和4-羟基-2-喹诺酮(2f-i),并使用三乙氧基甲烷和苯胺将其转化为烯胺3。3与腈4a-h的缩合反应生成2 H,5 H-吡喃并[3,2- c ]苯并吡喃-2,5-二酮(5a-r)或2 H,5 H-吡喃并[3,2- c ]喹啉-2,5-二酮(5s-x),显示出自发的和受激的荧光,最大值介于418和549 nm之间。7a,b(由2d,e和3-氧代丁酸乙酯合成)的荧光光谱证明了5中的吸电子3取代基的显着影响,与化合物21-r相比,其最大值急剧转变为蓝色。。
and the allenoate zwitterion 2, generated by addition of phosphine to acetylenedicarboxylates, undergo a cascade reaction sequence involving an unprecedented [5+3] annulation followed by deoxygenative rearrangementleading to dihydropyridine-fused benzopyrones. Unusual electronic control by the N-substituents of 1 directs the annulation pathway, leading to two different ring-systems. nitrones - dipolar
Discovery of two new classes of potent monoamine oxidase-B inhibitors by tricky chemistry
作者:F. Cagide、T. Silva、J. Reis、A. Gaspar、F. Borges、L. R. Gomes、J. N. Low
DOI:10.1039/c4cc08798d
日期:——
The discovery of potent and selective monoamine oxidase-B inhibitors for the management of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases is still a challenging endeavor. Herein, we report the discovery of two newclasses of potent and selective MAO-B inhibitors based on chromane-2,4-dione and chromone-3-carboxamide scaffolds.
Hamdi, Maamar; Granier, Patrick; Sakellariou, Reine, Journal of Heterocyclic Chemistry, 1993, vol. 30, # 4, p. 1155 - 1158
作者:Hamdi, Maamar、Granier, Patrick、Sakellariou, Reine、Speziale Vincent
DOI:——
日期:——
Beitr�ge zur Chemie der Enaminoketone, 15. Mitt.: Die Dreikomponentensynthese von Hydrazinomethylenchromandionen und eine reduktive N-N-Bindungsspaltung von Phenylhydrazin
作者:H. Junek、C. Reidlinger
DOI:10.1007/bf00807432
日期:1995.5
The three-component reaction of 4-hydroxycoumarin, ethylorthoformiate, and different substituted hydrazines is described. p-Nitrophenylhydrazine, hydrazides and phenylsemicarbazide lead to the expected hydrazinomethylene-chromandiones 2a-f. Reaction of 4-hydroxycoumarin, ethylorthoformiate, and phenylhydrazine or p-tolyl-hydrazine does not yield 2, but the anilino-methylene-chromandiones 6a-b. This indicates a reductive N-N bond cleavage to aniline and ammonia under mild conditions.