Synthesis and Structures of 6-Aryl-1,5-dimethoxycarbonyl-2-methyl-4-morpholino-1,3-cyclohexadienes and Related Compounds.
作者:Hajime NITTA、Koichi TAKIMOTO、Ikuo UEDA
DOI:10.1248/cpb.40.858
日期:——
Reaction of benzaldehyde (1a) with methyl acetoacetate (2) in the presence of morpholine (or piperidine) and AcOH in refluxing C6H6 yielded a new condensation product, 1, 5-dimethoxycarbonyl-2-methyl-4-morpholino (or piperidino)-6-phenyl-1, 3-cyclohexadiene (3a or 10a), along with a usual product, benzylideneacetoacetate (4a). Under the conditions determined as optimum, 3a was prepared in 86% yield. However, reaction of 1a and 2 in the presence of morpholine (or piperidine) in EtOH solution yielded 4a, a poly-substituted cyclohexanone derivative (5a) and a cyclohexenone derivative (7a), while the production of 3a was not detected. Compound 3a (or 10a) was also prepared by an alternative procedure of condensation of 5a or 6a with morpholine (or piperidine) in the presence of TiCl4. Compound 6a was prepared by dehydration of 5a under acidic conditions. Acid hydrolysis of 3a afforded 6'a, which is the C-4 epimer of 6a. The configurations of 3a, 6a and 6'a were assigned on the basis of the proton nuclear magnetic resonance (1H-NMR) spectra. Mechanisms of the formation of 3a are discussed. Some of 3 and related compounds exhibited potent calcium channel-blocking activity.
Design of a graphene oxide-SnO<sub>2</sub> nanocomposite with superior catalytic efficiency for the synthesis of β-enaminones and β-enaminoesters
作者:Aniket Kumar、Lipeeka Rout、Rajendra S. Dhaka、Saroj L. Samal、Priyabrat Dash
DOI:10.1039/c5ra03363b
日期:——
A graphene–SnO2 nanocomposite has been synthesized by a solvothermal method, which is a more effective and less time-consuming catalyst for the synthesis of β-enaminones and β-enaminoesters.
A series of 1, 1'-biphenyl-2, 6-dicarboxylic acid diesters were synthesized and examined for their inhibitory activity on guinea-pig detrusor muscle contraction at electrical field stimulation in vitro. Among them, 6-isopropyl 2-methyl 3-hydroxy-5-methyl-2'-nitro-(1, 1'-biphenyl)-2, 6-dicarboxylate, FR75513 (8a) was one of the potent compounds (IC50=3.3×10-6 g/ml). This compound (8a) exhibited a strong inhibitory activity on detrusor contraction after intravenous administration in anesthetized rats (ID50=0.04 mg/kg).
The cycloaddition reaction of nitrones to unsaturated methylsulfones and substituted crotonic esters gives a sole product or a mixture of tri- or tetra-substituted isoxazolidines, such that with disubstituted dipolarophiles the regiochemistry is dependent upon the nitrone and the vicinal electron-withdrawing group (CN or CO2Me) but with trisubstituted olefins, regiospecific cycloadditions are observed
Effect of solvent ratio and counter ions on the morphology of copper nanoparticles and their catalytic application in β-enaminone synthesis
作者:Aravind L. Gajengi、Takehiko Sasaki、Bhalchandra M. Bhanage
DOI:10.1039/c6ra22017g
日期:——
selective copper nanoparticles (NPs) using a microwave irradiation method, using diverse ratios of an ethylene glycol (EG)/water system. The solvent ratio of EG/water plays a pivotal role in the selective formation of CuO NPs. The alteration of the counter ion of the copper precursor leading to the selective synthesis of copper (CuO, Cu2O, Cu(OH)2) NPs has been observed. The synthesized copper NPs are