Catalyst-free synthesis of benzodiazepines and benzimidazoles using glycerol as recyclable solvent

Recent Advances in the Use of Glycerol as Green Solvent for Synthetic Organic Chemistry

“…Remarkably, after removing the insoluble products 4 from the reaction media through a simple decantation, glycerol could be reutilized without loss of effectiveness (up to four consecutive runs). Similarly, catalyst-free condensation of o-phenylenediamine with several aldehydes and enolizable ketones was found to proceed cleanly in glycerol to furnish the corresponding benzimidazoles 5 and benzodiazepines 6, respectively (Scheme 7) [48]. As in the preceding case, after extraction of the final reaction products with a hexane/ethyl acetate mixture (95:5 v/v), glycerol could be reused without purification for further reactions (up to five runs).…”

Green and efficient method for the synthesis of 1,5-benzodiazipines using phosphate fertilizers as catalysts under free solvent

“…They have attracted special attention due to their important biological or pharmacological properties [1][2][3][4][5][6][7][8] and their wide field of application in different areas of medicine [9][10][11][12] and agriculture 13 . It was reported that the 1,5-benzodiazepines and its derivatives present interesting pharmacological and therapeutic properties.…”

One-pot, multicomponent synthesis of symmetrical Hantzsch 1,4-dihydropyridine derivatives using glycerol as clean and green solvent

“…In addition to this it does not distort the environmental processes. Not a long time ago, it was found that glycerol has been used for Heck and Suzuki coupling [26][27][28], Michael addition [29], Fridel-Crafts type addition, epoxide ring opening [30], synthesis of xanthenes [31] and very recently for the production of benzodiazepines and octahydroacridines [32,33]. Understanding the magnanimity of both 1,4-DHP's and glycerol, a new clean and green protocol has been discussed.…”