scholarly journals An Efficient Synthesis of Tetrahydrobenzo[b]pyran Derivatives Using Sulfonic Acid Functionalized Silica as an Efficient Catalyst

2011 ◽  
Vol 8 (1) ◽  
pp. 293-299 ◽  
Author(s):  
Ghodsi Mohammadi Ziarani ◽  
Alireza Abbasi ◽  
Alireza Badiei ◽  
Zeinab Aslani

Tetrahydrobenzo[b]pyran derivatives were efficiently synthesized by the reaction of appropriated aromatic aldehydes, malononitrile and dimedone in the presence of SiO2-Pr-SO3H as a nanoporous and recoverable solid acid catalyst, in good to excellent yields. Single crystal x-ray analysis conclusively confirmed the structure of the 2-amino-3-cyano-7,7-dimethyl-4-(4-methylphenyl)-5-oxo-4H-5,6,7,8-tetrahydro-benzopyran.

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 710 ◽  
Author(s):  
Xiaochuan Zou ◽  
Xuyuan Nie ◽  
Zhiwen Tan ◽  
Kaiyun Shi ◽  
Cun Wang ◽  
...  

In this paper, a solid acid catalyst (ZPS–PVPA–SO3H) was prepared by anchoring thiol group on zirconium poly(styrene-phenylvinyl-phosphonate)-phosphate (ZPS–PVPA), followed by oxidation of thiol groups to obtain sulfonic acid groups. The solid acid catalyst was characterized by XPS, X-ray, EDS, SEM, and TG-DSC. The successful preparation of sulfonic acid-functionalized ZPS–PVPA was confirmed. Subsequently, the catalytic performance of ZPS–PVPA–SO3H was investigated in the epoxidation of soybean oil. The results demonstrated that ZPS–PVPA–SO3H can effectively catalyze epoxidation of soybean oil with TBHP as an oxidant. Moreover, there was no significant decrease in catalytic activity after 5 repeated uses of the ZPS–PVPA–SO3H. Interestingly, the ZPS–PVPA–SO3H was kept in 2 mol/L of HCl overnight after the end of the seventh reaction, and the catalytic activity was gradually restored during the eighth to tenth cycles.


2013 ◽  
Vol 1 ◽  
pp. 194308921350716 ◽  
Author(s):  
Abbas Teimouri ◽  
Leila Ghorbanian

This study presents a simple highly versatile and efficient synthesis of various β-amino carbonyl compounds in the Mannich reaction of acetophenone with aromatic aldehydes and aromatic amines in the presence of nanosulfated zirconia, nanostructured ZnO, nano-γ-alumina, and nano-ZSM-5 zeolites as the catalyst in ethanol at moderate temperature. The optical properties of the nanostructured organic molecules were studied. The advantages of methods are short reaction times, milder conditions, easy workup, and purification of products by nonchromatographic methods. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of efficiency.


Author(s):  
Charishma Venkata Sai Anne ◽  
Karthikeyan S. ◽  
Arun C.

Background: Waste biomass derived reusable heterogeneous acid based catalysts are more suitable to overcome the problems associated with homogeneous catalysts. The use of agricultural biomass as catalyst for transesterification process is more economical and it reduces the overall production cost of biodiesel. The identification of an appropriate suitable catalyst for effective transesterification will be a landmark in biofuel sector Objective: In the present investigation, waste wood biomass was used to prepare a low cost sulfonated solid acid catalyst for the production of biodiesel using waste cooking oil. Methods: The pretreated wood biomass was first calcined then sulfonated with H2SO4. The catalyst was characterized by various analyses such as, Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray diffraction (XRD). The central composite design (CCD) based response surface methodology (RSM) was applied to study the influence of individual process variables such as temperature, catalyst load, methanol to oil molar ration and reaction time on biodiesel yield. Results: The obtained optimized conditions are as follows: temperature (165 ˚C), catalyst loading (1.625 wt%), methanol to oil molar ratio (15:1) and reaction time (143 min) with a maximum biodiesel yield of 95 %. The Gas chromatographymass spectrometry (GC-MS) analysis of biodiesel produced from waste cooking oil was showed that it has a mixture of both monounsaturated and saturated methyl esters. Conclusion: Thus the waste wood biomass derived heterogeneous catalyst for the transesterification process of waste cooking oil can be applied for sustainable biodiesel production by adding an additional value for the waste materials and also eliminating the disposable problem of waste oils.


2017 ◽  
Vol 95 (12) ◽  
pp. 1248-1252 ◽  
Author(s):  
Mohammad Ali Zolfigol ◽  
Mahdiyeh Navazeni ◽  
Meysam Yarie ◽  
Roya Ayazi-Nasrabadi

In this study, Fe3O4@SiO2/(CH2)3-[imidazolium-SO3H]Cl shows robust promoting capability in the synthesis of arylbispyranylmethane derivatives under mild and green conditions. Arylbispyranylmethanes were synthesized via efficient three-component reaction of various aromatic aldehydes with 4-hydroxy-6-methyl-2H-pyran-2-one. The nanomagnetic core-shell catalyst presented effective potential of at least eight times recycling applicability in the described synthetic procedure.


2010 ◽  
Vol 51 (22) ◽  
pp. 2959-2962 ◽  
Author(s):  
Khodabakhsh Niknam ◽  
Dariush Saberi ◽  
Maryam Nouri Sefat

2019 ◽  
Vol 7 (1) ◽  
pp. 55-80 ◽  
Author(s):  
Fatemeh Ghorbani ◽  
Seied Ali Pourmousavi ◽  
Hamzeh Kiyani

Background: Much attention has been focused on heterogeneous catalysts. Reactions with these recoverable and reusable catalysts are clean, selective with high efficiency. Among the heterogeneous solid acid catalyst in organic synthesis, Carbon-Based Solid Acids (CBSAs), which are important solid acid with many practical and research applications have been extensively studied. In this work, green Pistachio peel, a biomass waste, was converted into a novel carbon-based solid acid catalyst (Pis-SO3H). Objective: The aim of this work is to synthesize highly sulfonated carbon as an efficient, recyclable, nontoxic solid acid catalyst by simultaneous sulfonation, dehydration and carbonization of green Pistachio peel as biomass and investigate the catalytic activity of Pis-SO3H in acetalization, thioacetalization, acylation of aldehydes and synthesis of 3,3'-Arylmethylene-bis(4-hydroxycoumarin) derivatives. Method: Pis-SO3H was synthesized by an integrated fast one-step hydrothermal carbonization and sulfonation process in the presence of sulfuric acid. The characterization of the physicochemical properties of Pis-SO3H was achieved by XRD, FT-IR, FE-SEM, and elemental analysis. Results: The result of acid-base titration showed that the total acidity of the catalyst was 7.75 mmol H+g−1. This new heterogeneous catalyst has been efficiently used for the chemoselective thioacetalization, acetalization and acylation of aldehyde and the synthesis of biscoumarins under solvent-free conditions. All the reactions work easily in high yields. The antimicrobial activity of some of the biscoumarins was evaluated in screening by disk diffusion assay for the zone of inhibition. Conclusion: The catalytic activity of the Pis-SO3H was investigated during acetalization, thioacetalization, acylation and synthesis of biscoumarins. The results of protection of carbonyl groups and synthesis of biscoumarins in the present work offer effective alternatives for environmentally friendly utilization of abundant biomass waste.


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