＜正＞Acyclic nucleosides have been identified as a new class of antiviral agents with a broad spectrum of activi...
QU,Gui-Rong HAN, Su-Hui ZHANG, Zhi-Guang XUE, Feng GENG, Ming-Wei (Key Laboratory of Environmental Science and Technology of High Education of Henan Province, College of Chemical and Environmental Science, Henan Normal University, Xinxiang 453007)
Starting from tetraacetylribofuranose (Ⅰ) and 6-chloropurine (Ⅲ), in the presence ofp-toluenesulfonic acid as catalyst, the intermediate 2',3',5'-tri-O-acetyl-6-chloropurine nucleoside (Ⅲ) was synthesized for the first time under microwave irradiation in the yield of 80.1%. The title compounds 6-chloro-9-β-D-purinenucleoside (Ⅳ) and 6-methoxy9-β-D-purinenucleoside (Ⅴ) were easily obtained by treatment the intermediate (Ⅲ) with NH3/CH3OH and Na2CO3/CH3OH in the yields of 78.8% and 76.9%, respectively. Structures of Ⅳ and Ⅴ have been identified by 1H NMRand elementary analysis. The optimal conditions for condensation were as follows: n(Ⅰ): n(Ⅱ)= 1: 1, m(TsOH):m(6-chloropurine)=3 × 10-2, microwave irradiation at 595 W for 4.5 min, at 462 W for 1 min, at 119 W for 0.5 min;aminolysis condition for Ⅳ: room temperature for 5 min; alkaline hydrolysis conditions for Ⅴ: reflux for 5 h.……
A simple, efficient and eco-friendly method for the synthesis of thiosemicarbazones from thiosemicarbazides and aldehyde under microwave irradiation has been reported, and no solvent and catalyst were used. And the technique of microwave irradiation coupled with solvent-free condition proved to be a quite valuable method in the organic synthesis.
