10.1023/A:1026365104706
The research focuses on the rearrangement-cleavage reactions of ammonium salts containing a 3-methyl-2-naphthylmethyl group. The study investigates how these salts react under the influence of 25% aqueous potassium hydroxide at 90-92°C, suggesting that the aromatic ring of the 3-methyl-2-naphthylmethyl group is involved in the reaction. The experiments utilized various ammonium salts with different substituent groups (Ia-Ig) and monitored the formation of products such as dimethylamine and aldehydes, indicating rearrangement-cleavage involving the aromatic ring. The reactions' yields ranged from 10% to 40%, and the products were analyzed using techniques like IR and 1H NMR spectroscopy, mass spectrometry, gas-liquid chromatography (GLC), and thin-layer chromatography (TLC) to confirm their structures and purities. The study also explored side reactions like nucleophilic substitution and Stevens rearrangement, providing a comprehensive analysis of the reaction pathways and product formation.
10.1055/s-1987-27963
The research details a facile synthesis of ethyl 2-alkylindole-3-carboxylates and ethyl 3-alkylindole-2-carboxylates, which are significant intermediates in the synthesis of alkaloids and various heterocyclic compounds. The study reinvestigated an earlier synthesis method, utilizing readily accessible o-nitroarylaldehydes as starting materials. The researchers discovered that the previously reported deoxygenation products were incorrectly assigned and provided evidence supporting the correct structures through 'H-NMR and C-NMR spectral data. The study concluded that the ester group (-COOEt) migrates preferentially over alkyl groups in the cation A', and demonstrated that from a single easily available aldehyde, two different important indole carboxylic esters could be synthesized. Key chemicals used in the process include o-nitroarylaldehydes, ethyl 2-nitrocinnamates, tricthyl phosphite, dimethylamine, acetic acid, formaldehyde, and palladium on carbon.
10.3987/COM-88-4594
The research investigates the synthesis and reactivity of a series of N-substituted 4-amino-2(5H)-furanones derived from β-tetronic acid. The purpose of the study is to explore the Eschenmoser-Mannich reaction of these furanones, which has not been extensively examined previously, and to understand their potential for α-homologation and use as building blocks for heterocyclic compounds. The researchers synthesized various N-substituted 4-amino-2(5H)-furanones by reacting β-tetronic acid with different aliphatic and aromatic amines. These compounds were then subjected to the Eschenmoser-Mannich reaction, yielding corresponding Mannich bases quantitatively. The study concludes that the 4-amino-2(5H)-furanones exhibit improved reactivity at position 3, as evidenced by their electrophilic substitution reactions and the formation of Mannich bases. The researchers also explored the quaternization of these Mannich bases with methyl iodide, observing the formation of normal and intermolecular quaternary salts, particularly in the case of the 4-anilinofuranone system. The chemicals used in the process include β-tetronic acid, various amines (such as dimethylamine, methylamine, benzylamine, and aniline), Eschenmoser's salt, methyl iodide, and other reagents like potassium carbonate and sodium borohydride for different steps of the synthesis and reactions.
10.1021/ja01646a074
The study explores the isomerization of D-glucose to D-mannose using a resin catalyst in carbon dioxide-free water under nitrogen, yielding D-mannose phenylhydrazone. It also investigates the synthesis of amines derived from 3-phenyl-1-indanone through the Mannich reaction with various amines (dimethylamine, diethylamine, piperidine, and morpholine) and formaldehyde, resulting in low yields and unstable products. Further reductions and hydrogenations of these products led to the formation of indene derivatives and aminoalcohols, but no significant pharmacologic activity was observed. Additionally, the study examines the Mannich reaction of p-nitroacetophenone with different amines and formaldehyde, yielding p-(di)-alkylamino-p-nitropropiophenones, which were further reduced to aminoketones and reacted with phenylhydrazine to form pyrazolines.
10.1021/ja01130a039
The study investigates the reactions of various amines with p-quinonedibenzenesulfonimide (I). Different amines, such as morpholine, piperidine, dimethylamine, aniline, p-toluidine, p-phenylethylamine, and butylamine, are reacted with I under different solvent conditions (chloroform, benzene, ether) to produce a variety of products. The products formed depend on the specific amine used and the reaction conditions. For example, morpholine reacts with I to form compounds like 2,5-dimorpholino-p-phenylenedibenzenesulfonamide (A), 2,5-dimorpholino-p-quinonedibenzenesulfonimide (B), p-benzenesulfonamidophenylmorpholine (C), and p-phenylenedibenzene sulfonamide (D), with the relative amounts of each product varying based on the solvent used. The study also explores the oxidation and reduction of these products to further understand the reaction mechanisms and pathways. The research provides insights into the complex interactions between p-quinonedibenzenesulfonimide and different amines, revealing the formation of diverse compounds and the influence of experimental conditions on the reaction outcomes.
10.1016/j.carres.2006.06.016
The study focuses on the synthesis of novel σ-receptor ligands using methyl α-D-mannopyranoside as the starting material. This is the first time a monosaccharide has been utilized for the creation of such ligands, which have potential applications as antipsychotics, antidepressants, anticocaine agents, and antitumor agents. The researchers employed various chemicals in the synthesis process, including nitrile 7, which was transformed into hept-3-ulopyranoside dimethyl ketals 14 and 15 through two different synthetic routes. Amino substituents were introduced into position 3 after selective hydrolysis of the ketone dimethyl acetal. The study identified that a dichlorophenylacetamide moiety in position 7 and equatorially arranged amino substituents in position 3 were crucial for high σ1-receptor affinity and selectivity. The synthesized compounds were then tested for their affinity and selectivity towards σ1 and σ2 receptors, as well as their interaction with other receptor systems such as the phencyclidine binding site of the NMDA receptor, δ-opioid, and μ-opioid receptors. The most active compound in the series, an anomeric mixture of dimethylamines 26a/b, showed the highest σ1-receptor affinity with a Ki value of 21 nM. The study demonstrated the potential of using monosaccharides as building blocks for the development of new drugs with high σ1-receptor affinity and selectivity.
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F:Flammable;
