15 research outputs found
Fused and spiro nitrogen heterocycles of quinuclidine and its C-nucleosides
Quinuclidin-3-one (1) was used as a versatile intermediate for the synthesis of fused and spiro quinuclidine and its C-nucleosides. The reaction of 1 with formalin and secondary amines namely; morpholine, piperidine, and piperazine afforded the corresponding Mannich bases 2-4 in acid medium. Quinuclidino[3,2-b]pyran 5 has been synthesized via a selective cyclocondensation reaction between Mannich base of quinuclidinone hydrochloride 2 and malononitrile. The transformation of 1 with formalin and methylamine in molar ratio (1:20:2) afforded the spiro compound 7. Ring expansion of 2 under Schmidt reaction conditions gave the 1,3-diazabicyclo[3.2.2]nonanone derivative 6. Eventually, the synthesis of C-nucleosides 10, 12-14 were achieved by using aldohexoses and aldopentose catalyzed by zinc chloride, while, the bis-quinuclidine derivative 15 was obtained by using sodium carbonate. Newly synthesized compounds were characterized by IR, 1H NMR, and mass spectral data
An Easy Synthetic Approach to Construct Some Ebselen Analogues and Benzo[b ]selenophene Derivatives: Their Antioxidant and Cytotoxic Assessment:An Easy Synthetic Approach to Construct Some Ebselen Analogues and Benzo[b ]selenophene Derivatives: Their Antioxidant and Cytotoxic Assessment
Recent advances in the chemistry of selenium-containing heterocycles: Six-membered ring systems
Peculiar reaction behavior of 1,3-oxathiolan-5-one toward various reagents: Molecular modeling studies and in vitro antioxidant and cytotoxicity evaluation
<p>Chemical reactivity of 2-methyl-2-phenyl-1,3-oxathiolan-5-one (<b>1</b>) toward various reagents such as hydroxyaldehyde, ketone, α,β unsaturated carbonyl compounds, heterocyclic amine, hydrazine, and hydrazide to give unpredicative opened and fused heterocyclic systems was investigated. Moreover, treatment of compound <b>1</b> with bromoester to afford the respective fused system, 2-methyl-2-phenylfuro[3,2-d][1,3]oxathiol-5(6<i>H</i>)-one (<b>6</b>) was implemented. Besides, <sup>1</sup>H–<sup>1</sup>H nuclear overhauser effect spectroscopy was used for full confirmation of the compound <b>19</b>. In addition, the density functional theory modeling study outcomes were discussed and all of the new synthesized compounds were evaluated as antioxidants and cytotoxicity assay against hepatocellular carcinoma cell line.</p
Convenient synthesis, antimicrobial evaluation and molecular modeling of some novel quinoline derivatives
<p><i>α, β</i>-Unsaturated carbonyl compounds <b>2a, 2b, 3,</b> and <b>4</b> were synthesized by the Knoevenagel condensation between 2-substituted quionoline-3-carboxaldehyde <b>1a</b> and/or <b>1b</b> with active methylene compounds. In addition, the synthesis of azlactone is achieved starting from <b>1a</b> and <i>N</i>-acetylglycine. Synthesis of pyridine, pyrene, and pyrimidine derivatives <b>6</b>–<b>8</b> were accomplished via one-pot multicomponent reaction of <b>1b</b> with acetyl acetone, malononitrile, and ammonium acetate; acetophenone, malononitrile, and NaOH; or acetyl acetone and urea in acidic medium. The new synthesized compounds showed good antimicrobial activities. The DFT calculations have been used to predict the electronic properties of the studied compounds.</p