CRelevant articles and documents
All total 45 Articles be found
All total 45 Articles be foundBlount,Openshaw,Todd
, p. 286,289 (1940)
Easton,Dillard
, p. 1807,1809 (1963)
Schiff's Bases as Intermediates in the Hydrolytic Decomposition of 2-Alkyl-3-methyl-1,3-oxazolidines in Aqueous Acid
Pihlaja, Kalevi,Parkkinen, Aija,Loennberg, Harri
, p. 1223 - 1226 (1983)
The kinetics for the hydrolysis of 2-alkyl-3-methyl-1,3-oxazolidines have been examined spectrophotometrically in acidic solutions.The decomposition of the substrates to 2-methylaminoethanol and the corresponding aldehydes have been shown to proceed via stable intermediates which are kinetically and u.v.-spectroscopically very similar to the acyclic cationic Schiff's base derived from isobutyraldehyde and 2-methoxyethylmethylamine.The mechanisms for the formation and breakdown of the Schiff's base intermediate are discussed on the basis of pH-rate profiles, activation parameters, salt effects, and solvent deuterium isotope effects.
Electrochemical Reductive N-Methylation with CO2Enabled by a Molecular Catalyst
Rooney, Conor L.,Wu, Yueshen,Tao, Zixu,Wang, Hailiang
supporting information, p. 19983 - 19991 (2021/12/01)
The development of benign methylation reactions utilizing CO2 as a one-carbon building block would enable a more sustainable chemical industry. Electrochemical CO2 reduction has been extensively studied, but its application for reductive methylation reactions remains out of the scope of current electrocatalysis. Here, we report the first electrochemical reductive N-methylation reaction with CO2 and demonstrate its compatibility with amines, hydroxylamines, and hydrazine. Catalyzed by cobalt phthalocyanine molecules supported on carbon nanotubes, the N-methylation reaction proceeds in aqueous media via the chemical condensation of an electrophilic carbon intermediate, proposed to be adsorbed or near-electrode formaldehyde formed from the four-electron reduction of CO2, with nucleophilic nitrogenous reactants and subsequent reduction. By comparing various amines, we discover that the nucleophilicity of the amine reactant is a descriptor for the C-N coupling efficacy. We extend the scope of the reaction to be compatible with cheap and abundant nitro-compounds by developing a cascade reduction process in which CO2 and nitro-compounds are reduced concurrently to yield N-methylamines with high monomethylation selectivity via the overall transfer of 12 electrons and 12 protons.
Discovery of benzimidazole analogs as a novel interleukin-5 inhibitors
Boggu, Pulla Reddy,Kim, Youngsoo,Jung, Sang-Hun
, (2019/08/12)
A series of novel hydroxyethylaminomethylbenzimidazole analogs 5a-y were synthesized and evaluated for their IL-5 inhibitory activity using pro-B Y16 cell line. Among them, 2-(((4-(cyclohexylmethoxy)-1H-benzo[d]imidazol-2-yl)methyl)amino)butan-1-ol (5e, 94.3% inhibition at 30 μM, IC50 = 3.5 μM, cLogP = 4.132) and 3-cyclohexyl-2-(((4-(cyclohexylmethoxy)-1H-benzo[d]imidazol-2-yl)methyl)amino) propan-1-ol (5k, 94.7% inhibition at 30 μM, IC50 = 5.0 μM, cLogP = 6.253) showed the most potent inhibitory activity. The essential feature of SAR (Fig. 5) indicated that the chromenone ring can be replaced by a benzimidazole ring to maintain the inhibitory activity. In addition, the hydroxyethylaminomethyl group was suitable for the IL-5 inhibitory activity. Moreover, the hydrophobic substituents on carbon play an important role in the IL-5 inhibitory activity of these analogs. However, N-substituted analogs did not improve inhibitory activity. In addition, MTT assay of 5e and 5k with normal B lymphoblasts revealed that they had no significant effects on cell viability.
