Pd/ZrO2: An Efficient Catalyst for Liquid Phase Oxidation of Toluene in Solvent Free Conditions

Author(s):  
Mohsin Siddique ◽  
Muhammad Saeed ◽  
Mohammad Ilyas ◽  
Hussain Gulab

Abstract 0.1 % Pd/ZrO2 was synthesized and characterized by various physicochemical techniques and was successfully used as catalyst for solvent free oxidation of toluene in the presence of molecular oxygen using batch reactor. The catalytic performance of Pd/ZrO2 was explored in terms of effect of catalyst loading, reaction time, temperature and partial pressure of oxygen on oxidation of toluene in solvent free conditions. Pd/ZrO2 was found as a stable catalyst under the reaction conditions. Used catalyst exhibited the same catalytic efficiency as fresh catalyst under similar reaction conditions. Reaction was taking place according to Langmuir-Hinshelwood type of mechanism.

2008 ◽  
Vol 61 (3) ◽  
pp. 231 ◽  
Author(s):  
Babasaheb P. Bandgar ◽  
Neeta S. Joshi ◽  
Vinod T. Kamble ◽  
Sanjay S. Sawant

2,4,6-Trichloro-1,3,5-triazine-catalyzed convenient and efficient ring opening of epoxides with thiols under solvent-free conditions is described. Short reaction time, mild reaction conditions, inexpensive and readily available catalyst, and excellent yields of products are attractive features of this methodology.


2008 ◽  
Vol 86 (12) ◽  
pp. 1099-1104 ◽  
Author(s):  
Ahmed Kamal ◽  
M Naseer A Khan ◽  
Y VV Srikanth ◽  
K Srinivasa Reddy

A simple and highly efficient method has been developed for the tetrahydropyranylation of alcohols by their reaction with 3,4-dihydro-2H-pyran (DHP) using a catalytic amount (0.01–1 mol%) of aluminium triflate under solvent-free conditions. The effect of various factors like temperature, amount of the catalyst, and molar ratio of substrates on the reaction conditions has also been studied. The comparative study of tetrahydropyranylation of benzyl alcohol using various catalysts including some reported ones shows the efficiency of this catalyst.Key words: tetrahydropyranylation, aluminium triflate, alcohols, catalysis.


2015 ◽  
Vol 5 (2) ◽  
pp. 1307-1313 ◽  
Author(s):  
Upendra Nath Gupta ◽  
Hamed Alshammari ◽  
Nicholas F. Dummer ◽  
Robert L. Jenkins ◽  
Donald Bethell ◽  
...  

The oxidation of dec-1-ene is investigated under solvent-free conditions using gold nanoparticles supported on graphite and in a batch reactor in the presence of a radical initiator using oxygen from air as the terminal oxidant.


2017 ◽  
Vol 58 (2) ◽  
Author(s):  
Behrooz Maleki ◽  
Samaneh Sedigh Ashrafi

<p>The rapid and environmental synthetic route to produce 1<em>H</em>-indazolo[1,2-b] phthalazine-1,6,11-triones and 1<em>H</em>-pyrazolo[1,2-b]phthalazine-5,10-diones derivatives have been developed <em>via</em> multicomponent and one-pot reactions of various aldehydes, cyclic or acyclic 1,3-diketones with: <em>i)</em> phthalhydrazide or <em>ii)</em> phthalic anhydride-hydrazinium hydroxide using wet 2,4,6-trichlorotriazine (TCT) as catalyst under solvent-free conditions. Simple and mild reaction conditions, the use of a cheap catalyst and easy workup and isolation are notable features of this method.</p>


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammad Sadiq ◽  
Mashooq Khan ◽  
Muhammad Numan ◽  
Razia Aman ◽  
Saddam Hussain ◽  
...  

Activated carbon (AC) was prepared from carbonization of phosphoric acid soaked peanut shell at 380°C under inert atmosphere followed by activation with hydrogen peroxide. The AC was characterized by SEM, EDX, FTIR, TGA, and BET surface area and pore size analyzer. The potential of AC as a catalyst for solvent-free oxidation of cyclohexane to cyclohexanol and cyclohexanone (the mixture is known as KA oil) in the presence of molecular oxygen at moderate temperature was investigated in a self-designed double-walled three-necked batch reactor. The effect of different reaction parameters/additive was optimized. The maximum productivity value (2.14 mmolg−1 h−1, without base, and 4.85 mmolg−1 h−1, with 0.2 mmol NaOH) of the desired product was achieved under optimal reaction parameters: vol 12.5 mL, cat 0.4 g, time 14 h, oxygen flow 40 mL/min (pO2 760 Torr), stirring 1100 rpm, and temp 75°C. The AC shows recyclability for multiple runs without any significant loss in activity. Thus, the AC can be an efficient catalyst, due to low cost, ease of synthesis, easy recovery, nonleaching, and recyclability for multiple uses for the solvent-free oxidation of cyclohexane.


2018 ◽  
Vol 21 (8) ◽  
pp. 602-608 ◽  
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi

Aim and Objective: In the present work, 1, 1’-sulfinyldiethylammonium bis (hydrogen sulfate) as a novel room temperature dicationic ionic liquid was synthesized and used as a catalyst for xanthenediones synthesis. Material and Method: The dicationic ionic liquid has been synthesized using ethylamine and thionyl chloride as precursors. Then, by the reaction of [(EtNH2)2SO]Cl2 with H2SO4, [(EtNH2)2SO][HSO4]2 was prepared and after that, it was characterized by FT-IR, 1H NMR, 13C NMR as well as Hammett acidity function. This dicationic ionic liquid was used as a catalyst for the synthesis of xanthenediones via condensation of structurally diverse aldehydes and dimedone under solvent-free conditions. The progress of the reaction was monitored by thin layer chromatography (ethyl acetate/n-hexane = 3/7). Results: An efficient solvent-free method for the synthesis of xanthenediones has been developed in the presence of [(EtNH2)2SO][HSO4]2 as a powerful catalyst with high to excellent yields, and short reaction times. Additionally, recycling studies have demonstrated that the dicationic ionic liquid can be readily recovered and reused at least four times without significant loss of its catalytic activity. Conclusion: This new dicationic ionic liquid can act as a highly efficient catalyst for xanthenediones synthesis under solvent-free conditions.


2019 ◽  
Vol 16 (5) ◽  
pp. 776-786 ◽  
Author(s):  
Deepa ◽  
Geeta D. Yadav ◽  
Mohd J. Aalam ◽  
Pooja Chaudhary ◽  
Surendra Singh

Objective:DABCO salts were evaluated as catalysts for the Biginelli reaction between 4- methoxybenzaldehyde, urea and ethyl acetoacetate under solvent-free conditions. 1,4-Diazabicyclo [2.2.2] octane triflate was found to be a simple, inexpensive, highly efficient catalyst for Biginelli reaction for a variety aromatic aldehyde with urea and ethyl acetoacetate at 80°C afforded corresponding 3,4-dihydropyrimidinones in 50-99% yields after 30-120 minutes. 1,3-Cyclohexadione was used in place of ethyl acetoacetate in the absence of urea this methodology is giving hexahydro xanthene derivatives in good to excellent yields after 3-4 hours.Methods:DABCO salt 4 (5 mol%), 4-methoxybenzaldehyde (0.73 mmol) and urea (0.73 mmol) were stirred for 10 minutes at 80°C, then ethyl acetoacetate (1.5 equiv.) was added and reaction mixture was stirred at 80°C for specified time. The resulting solution was stirred continuously and progress of the reaction was followed by TLC. The crude reaction mixture was purified by flash column chromatography on silica gel (hexane/ethyl acetate (1:2)) to give pure desired product.Results:Reaction conditions of the Biginelli reaction were optimized using 4-methoxybenzaldehyde (0.73 mmol), urea (0.73 mmol), and ethyl acetoacetate (5 equiv.) as model substrates catalyzed by 1,4-Diazabicyclo [2.2.2] octane triflate (5 mol%) in a different solvents, screening of different catalysts and different temperatures. Neat condition was found to be the best for the Biginelli condensation and corresponding 3,4- dihydropyrimidinones was obtained in good to excellent yields. When the reaction was carried out with benzaldehyde derivatives and cyclohexane-1,3-dione in place of ethyl acetoacetate in the absence of urea, solely corresponding hexahydro xanthene derivatives were obtained in 61-91% yields.Conclusion:In conclusion, we have applied salts of 1,4-Diaza-bicyclo [2.2.2] octane as catalysts in the Biginelli condensation and corresponding 3,4-dihydropyrimidinones were obtained in 50- 99% yields under solvent free conditions. This methodology is having advantages like simple work-up; low loading of catalyst and reaction was performed at moderate temperature under solvent-free conditions.


1999 ◽  
Vol 23 (3) ◽  
pp. 236-237
Author(s):  
Habib Firouzabadi ◽  
Babak Karimi ◽  
Mohammad Abbassi

Active manganese dioxide and commercially available barium manganate are used for the efficient oxidation of benzylic and aromatic allylic alcohols and biaryl acyloins under solvent-free conditions.


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