A convenient method for the synthesis of 3,6-dihydroxy-benzene-1,2,4,5-tetracarboxylic acid tetraalkyl esters and a study of their fluorescence properties
作者:Aswathy L. Balachandran、Vidya Sathi、Ani Deepthi、Chettiyam V. Suneesh
DOI:10.3998/ark.5550190.p009.843
日期:——
A mild, efficient and simple method for the synthesis of 3,6-dihydroxy-1,2,4,5-tetracarboxylic tetraalkyl esters using cerium(IV) ammonium nitrate mediated oxidation of 1,3-acetone dicarboxylates has been developed. The detailed absorption and emission studies of the synthesized compounds reveal that these molecules have appreciable quantum yields and possess large Stokes shift values.
The properties of 1-hydroxy-4,5-arene-fused tropyliums were assessed based on experimental and theoretical investigations. An X-ray crystallographic analysis revealed a decrease of bond alternation in the seven-membered ring of 1-hydroxy-4,5-benzotropylium derivatives compared with that of the parent 4,5-benzotropones, which is indicative of an increase in aromaticity upon protonation. NICS and AICD
基于实验和理论研究评估了 1-羟基-4,5-芳烃稠合的 tropyliums 的性质。X 射线晶体学分析显示,与母体 4,5-苯并托酮相比,1-羟基-4,5-苯并托鎓衍生物的七元环中的键交替减少,这表明芳香性增加质子化。NICS 和 AICD 计算也支持 1-羟基-4,5-芳烃稠合的 tropylium 的芳香性增加。还测定了一系列 1-羟基-4,5-芳烃稠合的托鎓衍生物的 p K a值。
Zur Umsetzung von Aceton-1,3-dicarbonsäure-dialkylestern und 1,3-Diacetyl-aceton mit Stickstoffoxiden
作者:Bernard Unterlhalt、Ulf Pindur
DOI:10.1002/ardp.19763091003
日期:——
Aceton‐1,3‐dicarbonsäure‐dialkylester 4a‐reagieren mit Distickstofftrioxid/Salpetersäure zu den kristallinen 3,5‐Dialkoxycarbonyl‐4‐oxo‐4H‐pyrazol‐1,2‐bis‐oxiden 5a‐d und den öligen Dialkoxycarbonyl‐furoxanen 6a‐d. 4e‐f ergeben nur 6e‐f. Aus 1,3‐Dacetyl‐aceton (7) und Distickstofftetroxid entsteht das symmetrische 3,5‐Diacetyl‐4‐oxo‐4H‐pyrazol‐1,2‐bis‐oxid (8).
An expedient synthesis of spirooxindoles incorporating 2-amino pyran-3-carbonitrile unit employing dialkyl acetone-1,3-dicarboxylates
作者:Monisha Satheesh、Aswathy L. Balachandran、Parvathi R. Devi、Ani Deepthi
DOI:10.1080/00397911.2017.1416143
日期:2018.3.4
ABSTRACT Spirooxindoles are a class of molecules possessing significant biological effects such as antiviral, antifungal, antibacterial and anticancer properties. Herein we report a series of spirooxindole molecules having 2-amino pyran-3-carbonitrile and with two ester groups. These molecules were prepared by the reaction of dialkyl acetone-1,3-dicarboxylate and isatilidenes in the presence of triethyl
Process for producing optically active tropinonemonocarboxylic acid ester derivative
申请人:NIHON MEDI-PHYSICS CO., LTD.
公开号:US20030065183A1
公开(公告)日:2003-04-03
An optically active tropinonemonocarboxylic acid ester derivative useful as an intermediate for synthesis of optically active tropane derivatives was obtained by reacting succindialdehyde with an organic amine and acetonedicarboxylic acid ester to obtain a tropinonedicarboxylic acid ester derivative, and then subjecting this derivative to enzyme-catalyzed asymmetric dealkoxy-carbonylation. Since anhydroecgonine methyl ester derived from the optically active tropinone-monocarboxylic acid ester derivative by reduction and dehydration had the same direction of optical rotation as in the case of anhydroecgonine methyl ester obtained from natural cocaine, it was proved that the obtained optically active tropinonemonocarboxylic acid ester derivative had the same absolute configuration as that of natural cocaine. The yield of the optically active tropinonemonocarboxylic acid ester derivative from the asymmetric dealkoxycarbonylation was 30 to 50 mol %, and its optical purity was 70 to 97% ee. In addition, it was found that a crystalline optically active anhydroecgonine carboxylic acid ester derivative can be obtained by reducing and then dehydrating the optically active tropinonemonocarboxylic acid ester derivative and that its optical purity can easily be increased by recrystallization.