First Gewald reaction ignited by sodium polysulfide: greener ultrasound-promoted synthesis of substituted 2-aminothiophenes in the absence of catalyst
摘要:
In this paper, a modified and facile Gewald reaction triggered by sodium polysulfide in the absence of catalytic base was developed. This approach involves a one-pot ultrasound-irritated aqueous reaction between ketones or aldehydes, malononitrile, and sodium polysulfide, which are converted into the corresponding 2-aminothiophene derivatives in moderate to high yields. In comparison with conventional methods, the prominent features of this sonocatalyzed procedure are experimental simplicity, good functional group tolerance, atom efficiency, and the use of water as a green solvent.[GRAPHICS].
Thienylharnstoff-Derivate der Formel (I)
in welcher
X und R bis R5 die in der Beschreibung angegebenen Bedeutungen haben, und deren Säureadditions-Salze, sowie deren Verwendung als Schädlingsbekämpfungsmittel im Pflanzenschutz.
Die Verbindungen der Formel (I) können hergestellt werden, indem man z.B. geeignete Thienylamine mit geeigneten Iso(thio)cyanaten umsetzt oder geeignete Thienyli- so(thio)cyante mit geeigneten Aminosäuren bzw. deren Säureadditionssalzen gegebenenfalls in Gegenwart eines Katalysators und gegebenenfalls in Gegenwart von Verdünnungsmitteln umsetzt und gegebenenfalls physiologisch verträgliche Säuren addiert.
式(I)的噻吩基脲衍生物(其中 X 和 R 至 R5 具有说明中给出的含义)及其酸加成盐,以及它们在植物保护中作为杀虫剂的用途。 式(I)的化合物可通过例如合适的噻吩基胺与合适的异(硫代)氰酸酯反应,或通过合适的噻吩基如此(硫代)氰酸酯与合适的氨基酸或其酸加成盐反应来制备,如果合适的话,可在催化剂存在下进行,如果合适的话,可在稀释剂存在下进行,如果合适的话,可加入生理上可耐受的酸。
A facile and practical one-pot synthesis of multisubstituted 2-aminothiophenes via imidazole-catalyzed Gewald reaction
A simple and efficient procedure was developed for the synthesis of multisubstituted 2-aminothiophene derivatives. In the presence of catalytic amount of imidazole, ketones or aldehydes, dicyanomethane and elemental sulfur were converted into the corresponding 2-aminothiophene derivatives in moderate to high yields in DMF at 60 degrees C. (C) 2011 Elsevier Ltd. All rights reserved.
US4180503A
申请人:——
公开号:US4180503A
公开(公告)日:1979-12-25
US4692461A
申请人:——
公开号:US4692461A
公开(公告)日:1987-09-08
First Gewald reaction ignited by sodium polysulfide: greener ultrasound-promoted synthesis of substituted 2-aminothiophenes in the absence of catalyst
作者:Chengyuan Liang、Dong Lei、Xiuzhen Wang、Qingqing Zhang、Qizheng Yao
DOI:10.1080/17415993.2012.754892
日期:2013.10.1
In this paper, a modified and facile Gewald reaction triggered by sodium polysulfide in the absence of catalytic base was developed. This approach involves a one-pot ultrasound-irritated aqueous reaction between ketones or aldehydes, malononitrile, and sodium polysulfide, which are converted into the corresponding 2-aminothiophene derivatives in moderate to high yields. In comparison with conventional methods, the prominent features of this sonocatalyzed procedure are experimental simplicity, good functional group tolerance, atom efficiency, and the use of water as a green solvent.[GRAPHICS].