Pd/C-catalyzed, copper-free Sonogashira coupling: one-pot synthesis of 1-aryl-4-(2-phenylethynyl)[1,2,4]triazolo[4,3-a]quinoxalines in water
نویسندگان
چکیده
ABSTRACT Copper-free, Pd/C-catalyzed, one-pot reaction of 2,3-dichloroquinoxaline with hydrazine hydrate, bromine, phenylacetylene, and a variety of aldehydes provides an efficient and direct method for the preparation of 1-aryl-4-(2-phenylethynyl)[1,2,4]triazolo[4,3-a]quinoxalines in water at 70 °C. This methodology involves the use of inexpensive reagents or catalysts, and thus permits a new and practical access to triazolo[4,3-a]quinoxalines. GRAPHICAL ABSTRACT
منابع مشابه
An efficient three component one-pot synthesis of 5-amino-7-aryl-7,8-dihydro-[1,2,4] triazolo[4,3-a]-pyrimidine-6-carbonitriles.
A series of novel 5-amino-7-aryl-7,8-dihydro-[1,2,4] triazolo[4,3-a]-pyrimidine-6-carbonitriles were synthesized by a one-pot reaction of 3-amino-1,2,4-triazole, malononitrile and aryl aldehydes in the presence of 20 mol% NaOH in ethanol under heating or ultrasonic irradiation. The structures of the target compounds were confirmed by inspection of their (1)H- NMR, (13)C-NMR, IR and MS spectra. ...
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