Dibenzodiazepines in reactions of 2-acetyl-dimedone with 3,4-diaminobenzophenone

Efficient, environmentally benign, one-pot procedure for the synthesis of 1,5-benzodiazepine derivatives using N-methyl-2-pyrrolidonium hydrogen sulphate as an ionic liquid catalyst under solvent-free conditions

“…To highlight the advantages of this newly developed method, we have compared the results of the current study with those reported in literature for the same transformation using different conditions [20][21][22][23][24][25] (Table 1) When the reaction was carried out under solvent-free conditions at 60 °C, the product was isolated in 55% yield ( Table 2, entry 9). Furthermore, when the reaction was conducted in the presence of 0.14 g of the [H-NMP][HSO4] catalyst at 100 °C, the desired product 3e was isolated in a 85% yield ( The results of the optimization experiments indicated that the MCR was being catalyzed much more effectively by [H-NMP][HSO4] that any of the other catalysts tested, because the desired product was obtained in much higher yields over shorter reaction times when the reaction was conducted in the presence of this IL catalyst ( Table 2, entries 1-12).…”

“…For example, 1,5-dibenzodiazepine derivatives have been reported to exhibit inhibitory activities towards hepatitis C virus (HCV) NS5B [8] and HIV-1 protease [9,10], as well as finding numerous applications in medicinal chemistry [11], where they have been used as antiinflammatory [12], hypnotic [13], anticoagulant [14], antibacterial [15], antidepressant [16], antiepileptic [17,18] and analgesic [19] agents. Several methods have been reported for the synthesis of 1,5-benzodiazepine derivatives via the condensation of o-phenylenediamine and dimedone with various aldehydes or ketones in the presence of a wide variety of Brӧnsted acid catalysts, including acyl chlorides [8,9] oxalic acid in water [20], acetic acid in refluxing ethanol [21,22], HCl in ethanol [23], acetic acid in toluene [24] and H2SO4 in water [25]. Several other methods have also been developed for the synthesis of 1,5-benzodiazepine derivatives, such as the cycloaddition reaction of 2,2-dihydroxy-1-phenylethanone with an o-phenylenediamine derivative and dimedone [26], the hetero-Cope rearrangement and the condensation of a 2-formyl benzoic acid substrate with an o-phenylenediamine derivative and tetronic acid in water under microwave irradiation conditions [27].…”

Fe3O4@SiO2‐CeCl3 Catalyzed Chemoselective Synthesis of Functionalized 3‐Substituted‐1,5‐Benzodiazepines via One‐pot Multicomponent and Domino Reactions

“…A number of methods have been developed for the synthesis of 1,5‐benzodiazepines. It has been carried out by condensation of 1,2‐phenylenediamine with 1,3‐dicarbonyl compounds, 3‐haloalk‐2‐enones, and alk‐2‐ynones [ 11,12 ] under various conditions such as oxalic acid in organic solvents, acetic acid in ethanol under reflux, [ 13 ] acetic acid in toluene, [ 14 ] HCl in ethanol, [ 15 ] and H 2 SO 4 in ethanol. [ 16 ] Most of these procedures rely on liquid protic acid catalysts, which pose many drawbacks such as the predicament of waste disposal.…”

An NMR Study of the Kinetics of 1,4-N,N‘-Migration of the Acyl Group Vinylogs on Aromatic 1,2-Diamines

“…[4][5][6] Specifically, 2,3-diaminopyridine (1) and 2-formyldimedone (2) were used to synthesize 2-(2-amino-3-pyridylaminomethylene)-( 3) and 2-(3-amino-2-pyridylaminomethylene)-5,5-dimethyl-1,3-cyclohexanedione (4). [1][2][3] Both compounds were separated from the reaction mixture by chromatography and structurally characterized by IR and NMR spectroscopy. They were shown to be rigid amino vinyl ketones having a 3 J(H,H) CH-NH ≈ 12-13 Hz, stabilized with an intramolecular hydrogen bond of the type N-H‚‚‚O ) δ (NH ≈ 12-13 ppm).…”

“…As part of our continuing studies of the reactions of aromatic 1,2-diamines with 2-acyl-1,3-cyclandiones, − the reactions of 2,3-diaminopyridine were attempted with 2-acyl-1,3-cyclohexanediones to produce pyrido[2,3- b ][1,4]benzodiazapine derivatives. This class of compounds have been shown to exhibit a wide range of biological activity. − …”