Refernces
10.1016/S0040-4039(00)94151-0
The research focuses on the development of a novel and versatile synthesis method for heterocyclic aldehydes using dialkyl 3-oxo-1-alkenyl-phosphonates. The primary purpose of this study is to explore a three-step transformation process that begins with the preparation of 1,2-epoxy-3-oxoalkyl-phosphonates from 1-alkenyl-phosphonates. These epoxyphosphonates then react with ambident nucleophiles, such as thiourea, 2-amino-pyridine, 2-amino-pyrimidine, and ethyl 2-pyridylacetate, to form dialkyl 1-hetaryl-1-hydroxymethyl-phosphonates. The final step involves mild alkaline treatment to yield the desired heterocyclic aldehydes. The study concludes that α-hydroxyalkyl-phosphonates are significant synthons for carbonyl functions, and the method provides a new route for generating carbonyl units.
10.1021/ja010638q
The research aimed to study the conformational behavior and hydrogen-bonding interactions of heterocyclic ureas. The purpose was to understand the folding and unfolding processes of these molecules, which could mimic the helix-to-sheet transition seen in peptides and potentially in hypothetical naphthyridinylurea oligomers. The study involved the synthesis of various heterocyclic ureas (1-7) and their hydrogen-bonding complements, using chemicals such as 2-aminopyridine, aminonaphthyridine, triphosgene, 4-(dimethylamino)pyridine (DMAP), and butyl isocyanate. The conclusions revealed that these ureas can form intramolecular hydrogen bonds, leading to folded structures, but can also unfold and form multiply hydrogen-bonded complexes under certain conditions, such as high concentrations or in the presence of complementary molecules.
10.1021/acs.orglett.5b02966
The study presents a novel annulation method for synthesizing electron-deficient imidazo[1,2-a]pyridines and related heterocycles under mild conditions. The process involves treating 2-aminopyridines with a dimethylketal tosylate in acetonitrile at elevated temperatures (80?140 °C) in the presence of catalytic Sc(OTf)3, yielding the desired imidazo[1,2-a]pyridine products in good yields. This method is particularly useful for electron-poor 2-aminopyridines and offers an alternative to the traditional synthesis involving bromoketones with electron-rich and -neutral substrates. The study explores the scope and mechanism of the reaction, discussing the role of various additives and solvents in the cyclization process. The chemicals used in the study include 2-aminopyridines, dimethylketals (specifically tosyl ketal 3), and the catalyst Sc(OTf)3, which serve to facilitate the formation of the imidazo[1,2-a]pyridine ring system through an imine intermediate pathway.
10.3184/174751911X13026260434797
The study presents the synthesis and characterization of novel N-substituted 2-methylimidazo[1,2a]pyridine-3-carboxamides, which are nitrogen bridge-head heterocycles containing an imidazole[1,2a]pyridine ring. These compounds are significant in pharmaceuticals due to their diverse therapeutic activities, including as inhibitors of UV-induced keratinocytic apoptosis, antiviral agents, inhibitors of gastric H+/K+-ATPase, IRAK-4 inhibitors, HIF-1α prolyl hydroxylase inhibitors, and more. The chemicals used in the study include 2-aminopyridine, various amines for substitution, and reagents such as methyl 2-chloro-3-oxobutanoate, sodium hydroxide, thionyl chloride, and triethylamine. These chemicals served the purpose of synthesizing the target compounds through a series of reactions involving condensation, hydrolysis, and amidation. The synthesized compounds were then characterized using techniques like 1H NMR, MS, IR, and elemental analysis to confirm their structures and properties.
10.1002/adsc.201000895
The study presents an efficient method for the one-pot copper(I)-catalyzed synthesis of 3-aminocoumarin and its derivatives, which are biologically and pharmaceutically significant compounds. The researchers utilized salicylaldehyde, ethyl isocyanoacetate, and 2-aminopyridine as the primary starting materials, along with copper(I) salts (CuI, Cu(OTf)2, etc.) as catalysts, and pyridine as a base. These chemicals served to construct molecular scaffolds that are valuable in medicinal chemistry due to their potential applications as CNS depressants, antitumor, anti-inflammatory, and antimicrobial agents, as well as their use as fluorescent markers. The study aimed to develop a straightforward and efficient approach to these molecular scaffolds, which are considered "privileged structures" in the pharmaceutical and agrochemical industries.
10.1016/j.bmc.2008.07.049
The research aims to synthesize and evaluate a series of new isothiazol-3(2H)-one 1,1-dioxides with halogenated (mostly fluorinated) pyridinyl and pentafluorophenyl substituents at the 2-position for their inhibitory activity against human leukocyte elastase (HLE). The compounds were synthesized using an isothiazolium cyclization–oxidation route from 2-thiocyanato-1-carboxaldehydes and aminopyridines or pentafluoroaniline. The study found that compound 21 exhibited an IC50 value of 3.1 μM toward HLE, indicating significant inhibitory activity. Other enzymes like cathepsin G, trypsin, cathepsin L, and angiotensin-converting enzyme, as well as the serine esterases acetylcholinesterase and cholesterol esterase, were not inhibited by compound 21. The research concludes that these compounds, especially those with tetrafluoropyridinyl substitution, show promise as selective HLE inhibitors, which could be useful in treating inflammatory diseases associated with HLE overactivity.
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