Aroyl[bis(4-hydroxycoumarin-3-yl)]methanes in reactions with 1,2-diaminobenzenes
作者:N. N. Kolos、L. L. Gozalishvili、F. G. Yaremenko、O. V. Shishkin、S. V. Shishkina、I. S. Konovalova
DOI:10.1007/s11172-007-0359-7
日期:2007.11
The reaction of aroyl[bis(4-hydroxycoumarin-3-yl)]methanes with 1,2-phenylenediamines in PriOH is accompanied by the recyclization to 8-R-or 7-R-4-(2-hydroxyphenyl)-1,5-benzodiazepin-2-ones, whereas the reaction with o-phenylenediamine and its 4-methyl-substituted derivatives in MeOH produces organic ionic salts of the bis-coumarin anion with monoprotonated o-phenylenediamine as the cation.
A simple and green method is reported for the completely chemoselectivesynthesis of some new dicoumarol derivatives 3,3'-(2-aryl-2-oxoethylidene)bis[4-hydroxycoumarin]s} from the reaction of 4-hydroxycoumarin with arylglyoxals in a molar ratio of 2:1 respectively. The reactions efficiently promoted by titanium(IV) oxide nanoparticles as a heterogeneous catalyst via an on water process. Catalyst loading
New and known dicoumarols may be efficiently synthesized employing p-toluenesulfonicacid (p-TSA) as a solid acid catalyst from the reaction of 4-hydroxycoumarin with aryl glyoxal in water. This method offers direct access to structurally diverse coumarin derivatives in moderate to good yields (up to 65%). A total of five new compounds were synthesized.
An efficient synthesis of some new aroyl[bis(4-hydroxycoumarin-3-yl)] methanes (dicoumarols) based on the reaction of 4-hydroxycoumarin with arylglyoxals is described. The reactions were efficiently catalysed by tungstate sulfuric acid to afford the product in moderate to good yields (up to 65%).