α-Iodination of enaminones using the modified Johnson's procedure: the use of I2 and Et3N

Facile synthesis of α-iodo enaminones 2 was carried out by the use of iodine and triethylamine in methylene chloride in short time in excellent yields.     

Regioselective reactions of β-aminovinyl trifluoromethyl ketones with tosyl isocyanate

The NH- and α-CH-insertion reactions of tosyl isocyanate with N-monosubstituted and N,N-disubstituted trifluoromethyl-containing enaminones have been studied. The regioselectivity of N-tosylcarbomoylation of N-monosubstituted β-aminovinyl trifluoromethyl ketones depends on the structure of enaminones, the reaction temperature, the nature of solvent and catalyst. The Z configuration of fluorinated vinylogous sulphonylurea 3e was deduced from X-ray analysis. The reaction of N,N-disubstituted enaminone 5a with tosyl isocyanate gave the product mixture of electrophilic attack on either the α-CH- or the oxygen atom of COCF₃ group—vinylog of sulfonylurea 6a and tosylamide 7a, correspondingly.     

Synthesis of 4-(p-Methoxyphenyl)-β-Carboline,A New Inhibitor of Cellular Calcium Influx

4-(p-methoxyphenyl)-β-carboline was prepared in four steps from indole. The key step involved palladium-catalyzed dehydrogenation of a dihydro-β-carboline dichlorophosphinic acid salt. The success of the dehydrogenation was found to depend on the catalyst support.     

A New Route for the Synthesis of Substituted Pyridazines

Condensation of 4‐acetyl‐5,6‐diphenyl‐2,3‐dihydropyridzin‐3‐one (1) with dimethylformamide dimethylacctal (DMFDMA) afforded the enaminone 2. This could be converted into the pyrazolylpyridazine derivative 4 on reaction with hydrazine hydrate and into pyridazinylpyridazinone 7a,b via coupling with aromatic diazonium salts and subsequent treatment with active methylene compounds. The reaction of 6 with dimethyl acetylenedicarboxylate in the presence of triphenylphosphine afforded the pyridazinylpyridazine derivative 8. Compound 1 converted into 9 upon reflux in acetic acid in the presence of ammonium acetate and afforded 10 on reflux in acetic acid.     

One-Pot Synthesis of 3,4-Dihydropyridin-2-one via Michael Addition of in situ–Generated Enaminones

Herein we have reported a facile solvent-, catalyst-, and aldehyde-free, one-pot synthesis of 3,4-dihydropyridin-2-one from 1,3-diones using simple and mild reaction conditions. The substrate scope has been also extended to β-ketoesters.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

Efficient Synthesis of 2-Aminopyridine Derivatives: Antibacterial Activity Assessment and Molecular Docking Studies

A new and suitable multicomponent one-pot reaction was developed for the synthesis of 2-amino-3-cyanopyridine derivatives. Background: This synthesis was demonstrated by the efficient and easy access to a variety of substituted 2-aminopyridines using enaminones as key precursors under solvent-free conditions. Methods: A range of spectroscopic techniques was used to determine and confirm the chemical structures (FTIR, ¹H NMR, ¹³C NMR). The antimicrobial potency of synthesized compounds (2a–d) was tested using disk diffusion assays, and the Minimum Inhibitory Concentration (MIC) for the active compounds was determined against a panel of microorganisms, including Gram-positive and Gram-negative bacteria and yeasts. Moreover, a docking analysis was conducted by Molecular Operating Environment (MOE) software to provide supplementary information about the potential, as well as an ADME-T prediction to describe the pharmacokinetic properties of the best compound and its toxicity. Results: The results of the antimicrobial activity indicated that compound 2c showed the highest activity against Gram-positive bacteria, particularly S. aureus and B. subtilis whose MIC values were 0.039 ± 0.000 µg·mL⁻¹. The results of the theoretical study of compound 2c were in line with the experimental data and exhibited excellent antibacterial potential. Conclusions: On the basis of the obtained results, compound 2c can be used as an antibacterial agent model with high antibacterial potency.