An efficient method for the synthesis of dihydropyridine by hantzsch reaction with Fe/SiO2 nano heterogeneous catalysts
| dc.contributor.author | Rahman, Ateeq | |
| dc.contributor.author | Nehemia, P.N. | |
| dc.contributor.author | Nyambe, Moola M. | |
| dc.date.accessioned | 2022-02-16T06:36:44Z | |
| dc.date.available | 2022-02-16T06:36:44Z | |
| dc.date.issued | 2020 | |
| dc.description.abstract | An efficient method for the synthesis of dihydropyridines (DHPs) by Hantzsch reaction with Fe/SiO2 heterogeneous catalysts was developed. The Fe/SiO2 catalysts was prepared by impregnation method. The catalysts were characterized by IR and SEM instruments. The SEM results indicated that Fe/SiO2 nano spheres were formed. The reaction procedure involved reaction of aldehyde, ethyl acetoacetate (EAA), ammonium acetate (NH4OAc) and ethanol under reflux. The study was focused on optimizing reactions conditions: Standardization of catalyst, substrate of study and solvent study. In order to iden-tify the best active catalysts, five different ratios of catalyst were synthesized and evaluated for the ti-tle reaction under similar conditions. To standardize the active catalysts, different temperature condi-tions (i.e. room temperature, 60 ºC and 80 ºC) as well as catalysts amounts were evaluated. Under these established conditions, 2.5% Fe/SiO2 was the best active catalysts that resulted. Benzaldehyde and p-anisaldehyde were used to study the effect of having various substrates on the conversion and reaction time, especially the substituted aldehydes. The best results were obtained by reacting p-anisaldehyde with EAA, NH4OAc, and ethanol at 60 ºC with 0.3 grams of 2.5% Fe/SiO2 heterogeneous catalysts. Thin Layer Chromatography (TLC) monitoring of the reaction mixture showed no selectivity at high temperatures (80 ºC) with 15% Fe/SiO2. Standardization of solvent study was executed with two solvents, ethanol and acetonitrile. The product dihydropyridines were analyzed using gas chroma-tography-mass spectrometry (GC-MS). The melting points of the products were compared with authen-tic samples reported in the literature. Hence, the Fe/SiO2 catalysts is eco-friendly and economically de-veloped for the title reaction. | en_US |
| dc.identifier.citation | Rahman, A., Nehemia, P.N., & Nyambe, M.M. (2020). An efficient method for the synthesis of dihydropyridine by hantzsch reaction with Fe/SiO2 nano heterogeneous catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 15 (3), 617-630. | en_US |
| dc.identifier.uri | http://hdl.handle.net/11070/3123 | |
| dc.language.iso | en | en_US |
| dc.subject | Hantzsch reaction | en_US |
| dc.subject | dihydropyridines | en_US |
| dc.subject | Impregnated | en_US |
| dc.subject | Fe/SiO2 nano | en_US |
| dc.subject | Heterogeneous catalyst | en_US |
| dc.title | An efficient method for the synthesis of dihydropyridine by hantzsch reaction with Fe/SiO2 nano heterogeneous catalysts | en_US |
| dc.type | Article | en_US |