10.1080/10587250307066
The research presents the synthesis and characterization of a new mesogenic homologous series of Schiff base cinnamates that incorporate a naphthalene moiety. The study aimed to understand the impact of the ethylene linking group (cinnamoyl linkage) and the naphthalene moiety on the mesomorphic properties of these molecules. The reactants used in the synthesis included 4-(40-n-alkoxy cinnamoyloxy) benzaldehydes, 2-amino naphthalene, malonic acid, n-alkyl halide, K2CO3, p-hydroxy benzaldehyde, and solvents like ethanol, which were dried prior to use. The synthesized compounds were characterized using elemental analysis and various spectroscopic techniques, including infrared (IR), ultraviolet (UV), and proton nuclear magnetic resonance (1H NMR) spectroscopy. The study found that all synthesized compounds exhibited mesomorphism, and the mesophase properties were compared with other structurally related series. The results indicated that the presence of the naphthalene moiety and the cinnamoyl linkage influenced the mesophase transition temperatures and the overall thermal stability of the mesophases.
10.1177/1747519820911271
This study focused on the development of a three-step synthetic method for 2-arylamino-5-formylpyrimidines, which are an important building block for the preparation of various carbocyclic and heterocyclic rings in organic chemistry. The study aimed to improve on previous methods by utilizing bis(hexafluorophosphate) Arnold salt (1d), a safer, non-hygroscopic alternative to other Arnold salts, in the condensation reaction with N-arylguanidines. The researchers successfully synthesized a series of pyrimidine derivatives in moderate to good yields, demonstrating the potential use of bis(hexafluorophosphate) Arnold salt 1d in heterocyclic synthesis. The key chemicals used in the process included malonic acid as a starting material, aqueous ammonium hexafluorophosphate for precipitation of vinyl amidine salts, and various N-arylguanidines synthesized via a two-step method involving N,N′-bis-Boc-1H-pyrazole-1-carboxamidine and aromatic amines.
10.1016/j.bmc.2008.08.009
The study titled "Novel naphthoquinone and quinolinedione inhibitors of CDC25 phosphatase activity with antiproliferative properties" investigates the synthesis and biological evaluation of new naphthoquinone and quinolinedione derivatives designed to inhibit CDC25 phosphatase activity, which is implicated in cancer progression. The researchers introduced carboxylic or malonic acid groups to these derivatives to mimic the phosphate moieties of Cyclin-Dependent Kinase (CDK) complexes, aiming to enhance interactions with CDC25B. The most effective compounds exhibited inhibitory activity against CDC25B with IC50 values in the 10 μM range and showed cytotoxicity against HeLa cells. The study also explored the effects of these compounds on cell cycle progression, revealing that compound 2e had moderate effects on cell cycle distribution, consistent with CDC25 inhibitory effects. The research suggests that further chemical optimization of these derivatives could lead to potent CDC25 inhibitors with potential applications in cancer treatment.
10.1002/jhet.1994
The research focuses on the synthesis, substitution, and cyclization reactions of 5-unsubstituted pyrido[3,2,1-jk]carbazol-6-ones, which are part of the heterocyclic skeleton of natural products like Strychnos alkaloids and have attracted interest in pharmacological investigations and dyestuff chemistry. The study explores two main pathways for obtaining 5-unsubstituted pyrido[3,2,1-jk]carbazol-6-one 4 from carbazole (1) and malonic acid derivatives, either through a three-step synthesis involving 5-acetyl-pyridocarbazolone 3 or a one-step reaction from carbazole (1) and malonic acid/phosphoryl chloride. The research also investigates the substitution at C-5 of 4-hydroxypyrido[3,2,1-jk]carbazol-6-ones and further reactions leading to new and interesting structures. Key chemicals used in the process include carbazole, malonate derivatives, phosphoryl chloride, sodium azide, and various reagents for nitration, chlorination, and cyclization reactions. The conclusions drawn from the research highlight the ease of obtaining 5-unsubstituted pyrido[3,2,1-jk]carbazol-6-one 4 and the potential for further reactions at specific positions on the molecule, leading to biologically interesting structures.
Xn,
Xi
Xn:Harmful;
