چكيده لاتين
In this research, new Lewis acid based-deep eutectic solvents (LA-DES) were perpared, characterized and used for the synthesis of two important classes of nitrogen-containing heterocycles.
In the first part, diphenhydramine hydrochloride/CuCl deep eutectic solvent was synthesized and characterized by different techenics. Then its catalytic activity in the synthesis of tetrahydrocinnoline-5(1H)-one derivatives was investigated via a multicomponent reaction between dimedone, aryl aldehyde, and aryl/alkyl hydrazine in ethanol as a green solvent. Next, this catalyst was used for the synthesis of unsymmetric as well as mono- and bis-tetrahydrocinnoline-5(1H)-one derivatives. The synthesis of compounds containing both tetrahydrocinnoline-5(1H)-one and benzimidazole moieties from dialdehydes revealed the effectiveness and efficiency of this catalytic system. The one pot, rapid rate, high atom economy along with recyclability and reusability of the catalyst are other outstanding features of this method.
In the second part, diphenhydramine hydrochloride/CoCl2.6H2O deep eutectic solvent was synthesized and identified. This LA-DES was used as a catalyst in the synthesis of thiadiazolo[2,3-b]quinazoline derivatives via a three-component reaction between cyclic 1,3-dicarbonyl, aldehyde, and 5-aryl-1,3,4-thiadiazole- 2-amine under solvent-free conditions. To further investigate the catalytic activity of this LA-DES, the synthesis of thiadiazolo[2,3-b]quinazoline derivatives using 3-(5-amino-4,3,1-thiadiazol-2-yl)-2H-Chromene-2-one was investigated. Furthermore, the mono- and bis-thiadiazolo[2,3-b]quinazoline derivatives were obtained in good yeilds from dialdehyde and bis-1,3,4-thiadiazol-2-amine in the presence of this catalytic system. high yeilds, rapid rate, high atom economy, as most important advantages of this method.
To investigate the greenness and sustainability of the present protocols, a series of green metrics were calculated in the synthesis of tetrahydrocinnoline-5(1H)-one and thiadiazolo[2,3-b]quinazolin dervatives. Based on the obtained data, these methods can be considered as green protocols.
