10.1016/S0960-894X(00)00407-8
The research focuses on the facile and efficient one-pot synthesis of 4β-arylaminopodophyllotoxins, which are potent DNA topoisomerase II inhibitors with potential as anticancer agents. The study reports a series of 4β-arylamino-4'-O-demethylepipodophyllotoxins and 4β-arylaminoepipodophyllotoxins synthesized with significant stereoselectivity and improved yields, using the methanesulphonic acid/sodium iodide reagent system. Key reactants include podophyllotoxin, methanesulphonic acid, sodium iodide, and various arylamines. The methodology involves the conversion of podophyllotoxin to 4'-O-demethylepipodophyllotoxin and subsequent reaction with arylamines in the presence of bases like BaCO3, K2CO3, or CsCO3 to yield the desired 4β-arylaminopodophyllotoxin derivatives. The experiments utilize different solvents to manipulate the selectivity of 4'-O-demethylation, with CHCl3 favoring 4'-O-demethylation and C-4 epimerization, while MeCN leading to C-4 epimerization without 4'-O-demethylation. Analytical techniques used to characterize the synthesized compounds include infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), and mass spectrometry (MS). The synthesized compounds, such as NPF and W-68, exhibit improved topoisomerase II inhibition and cytotoxic activity compared to etoposide, a widely used anticancer drug.
10.1002/adsc.201900620
The research aims to develop a simple and efficient method for synthesizing 3-thiosubstituted pyrroles from homopropargylic amines and thiosulfonates through a tandem sulfenylation/cyclization process. The study explores the use of thiosulfonates as both substrates and oxidants, eliminating the need for external oxidants. The researchers optimized the reaction conditions, finding that a temperature of 100°C in toluene with sodium iodide (NaI) as a catalyst and trifluoroacetic acid (TFA) as an additive yielded the best results. The method demonstrated good functional group tolerance and produced a series of 3-thiosubstituted pyrrole derivatives in moderate to good yields. The study concludes that this direct synthesis method is a significant advancement in the field, offering a mild and efficient route for constructing C–C/C–S bonds, which could have broad applications in organic synthesis and medicinal chemistry.
10.1021/jm00388a012
This research aimed to synthesize and evaluate a series of 1-[1-(benzo-1,4-dioxan-2-ylmethyl)-4-piperidinyl]benzimidazolones with various substituents for their neuroleptic activity, specifically focusing on antiapomorphine effects and binding affinity to brain dopamine receptors, while also assessing their propensity to induce extrapyramidal side effects. The chemicals used in the synthesis included 2-(halomethyl)- or 2-[(tosyloxy)methyl]-1,4-benzodioxans, 1-(4-piperidinyl)benzimidazolones, and various reagents such as triethylamine, potassium carbonate, and sodium iodide. The research concluded that the most potent compounds were those with a 5-methoxy substituent, and that substituents increasing electron density in the phenyl ring by a mesomeric effect were best suited for enhancing neuroleptic potency.
10.1016/S0040-4039(98)02314-4
Ahmed Kamai et al. present a new method for the efficient and mild cleavage of allyl ethers to regenerate alcohols. The method involves using chlorotrimethylsilane and sodium iodide in acetonitrile, which generates iodotrimethylsilane in situ. The procedure is simple: an allyl ether solution is mixed with sodium iodide and chlorotrimethylsilane, stirred briefly, and then quenched with sodium thiosulphate. The products are extracted and purified to yield alcohols with high efficiency (93-98% yields). This method is advantageous over classical procedures as it is rapid, mild, and avoids the use of strongly basic or acidic conditions, making it a practical alternative for the deprotection of allyl ethers in organic synthesis.
Xi
Xi:Irritant;
