Reaction of Carboxylic Acid Hydrazides with 2,2′-(Carbonothioyldisulfanediyl)diacetic acid in Water as a “Green” Synthesis of N-(4-Oxo-2-sulfanylidene-1,3-thiazolidin-3-yl) Carboxamides
The article deals with the synthesis of some novel N-arylimidazo[1,2-a]pyrazine-2-carboxamides (7a-l) by condensation reaction of imidazo[1,2-a]pyrazine-2-carboxylic acid (5) with different aliphatic/aromatic amines (6a-l) by using 1-methylimidazole, Mukaiyama’s reagent and 2-chloro-1-methylpyridinium iodide under microwave irradiation conditions. A new series of compounds 7 have been prepared from 2-iodopyrazine (1). Compound 1 on purged with ammonia gas in the presence of Cu2O and K2CO3 furnishes pyrazin-2-amine (2), which is treated with ethyl 3-bromo-2-oxopropanoate (3) to produce ethyl imidazo[1,2-a]pyrazine-2-carboxylate (4), which on hydrolysis with NaOH yields imidazo[1,2-a]pyrazine-2-carboxylic acid (5). The structures of the newly synthesized compounds have been elucidated on the basis of spectral (IR, 1H and 13C NMR and MS) and analytical data. Compounds 7a-l have also been screened for their antimicrobial activity. Some of the compounds exhibit promising antimicrobial activity
The Passerini three-component condensation among a carboxylic acid (1), an aldehyde or ketone (2), and an isocyanide (3) was carried out for the first time in an ionic liquid, [bmim][BF4], and a series of acyloxycarboxamides were obtained through this reaction. The method presented herein has the advantages of high efficiency, a greener nature, and a simple operational procedure. Moreover, the ionic liquid can be easily recovered and reused for several runs without obvious loss of efficiency.Key words: Passerini reaction, acyloxycarboxamides, ionic liquid, green synthesis.
Abstract
Synthetic methods used to generate substituted anilines and quinazolines, both privileged pharmacological structures, are cumbersome, hazardous or, in some cases, unavailable. We developed a straightforward method for making isatoic anhydride-8-amide from isatin-7-carboxylic acid as a tool to easily produce a range of quinazoline and substituted aniline derivatives using adaptable pH-sensitive cyclization chemistry. The approaches are inexpensive, simple, fast, efficient at room temperature and scalable, enabling the synthesis of both established and new quinazolines and also highly substituted anilines including cyano derivatives.
Green Synthesis and Antimicrobial Activity of Some Novel
N-Arylimidazo[1,2-a]pyrazine-2-Carboxamide Derivatives