Synthesis Of 2-methylpyrazine Research Articles

Synthesis of 2-Methylpyrazine Using Crude Glycerol over Zn-Cr-O Catalyst: A Value Addition Process for the Utilization of Biodiesel By-Product

Mixed oxides of ZnO and Cr2O3 with varied mole ratios were synthesized, characterized, and evaluated for the dehydrocyclization of crude glycerol for the production of 2-methylpyrazine (2-MP). The Zn-Cr-O composition was optimized using the bulk and surface properties of the catalysts rationalized by BET-SA, XRD, XPS, H2-TPR, O2 pulse chemisorption, and Raman spectroscopic techniques to achieve a high rate of 2-MP.

A comparative study on the catalytic activity of ZnAl, NiAl, and CoAl mixed oxides derived from LDH obtained by mechanochemical method in the synthesis of 2-methylpyrazine

Mixed oxides (mo)-ZnAl; NiAl; CoAl (M2+/Al = 3 M ratio) were obtained from layered double hydroxides (LDH) precursors synthesized by mechanochemical method. The solids were characterized by XRD, DRIFT, H2-TPR, NH3/CO2-TPD and determination of textural properties by N2 adsorption-desorption isotherms. The catalytic activity was tested in the dehydration-cyclization of ethylenediamine with propylene glycol, followed by the dehydrogenation of the obtained piperazine, yielding the 2-methylpyrazine (2-MP) as the main reaction product. At 400 °C, the conversion of both reactants was quasi-total, but the yield to 2-MP was close to 90% on the solids with more active sites favoring dehydration-cyclization (mo-ZnAl and mo-CoAl).

Influences of pore size on production of 2-methylpyrazine over bifunctional CuO/ZnO/meso-SiO2 catalysts

Controllable crystallite size of CuO in CuO/ZnO/meso-SiO2 catalysts was successfully realized by impregnation method using mesoporous silica with different pore diameters as support. Characterization techniques such as N2 adsorption/desorption, X-ray diffraction, H2 temperature-programmed reduction, and potentiometric titration were employed to investigate the influences of pore size on textural properties, crystalline phases, reducibility, and acidity. Catalytic evaluation of synthesis of 2-methylpyrazine was carried out at 380 °C under atmospheric conditions. The best catalytic performance was achieved over catalyst CZ/S1 supported on the carrier with smallest pore size.

Synthesis of 2-Methylpyrazine Over Highly Dispersed Copper Catalysts

A series of CuCoAl catalysts were synthesized by co-precipitation and impregnation methods, tested in synthesis of 2-methylpyrazine (2-MP) and characterized by X-ray diffraction, N2 adsorption, thermo-gravimetry analysis, H2-temperature-programmed reduction, dissociative N2O adsorption and temperature-programmed oxidation. The precursors prepared by co-precipitation method shows a well-crystallized hydrotalcite. The study proves that the calcination temperature of hydrotalcite has a significant effect on the catalyst surface area, crystallite size and copper dispersion. In comparison with catalyst prepared by impregnation, the catalyst prepared by co-precipitation method calcined at 500 °C exhibits higher specific surface area, higher copper dispersion and the better reducibility. Consequently, CuCoAl catalyst derived from hydrotalcite is more active and selective for synthesis of 2-MP. Moreover, it shows the better stability due to the good resistance to coke formation. A novel solid base catalyst containing copper and spinel was prepared by the thermal decomposition of Cu–Co–Al hydrotalcite-like compounds for synthesis of 2-methylpyrazine

Synthesis of 2-methylpyrazine from cyclocondensation of ethylene diamine and propylene glycol over promoted copper catalyst

The 2-methylpyrazine was synthesized by catalytic reaction of ethylene diamine and propylene glycol at 380 °C. The alumina supported copper catalysts with promoter were prepared by impregnation method, characterized by ICP-AES, BET and TPR. The results demonstrated that the dehydrogenation was improved by addition of chromium promoter. The selectivity of 2-methylpyrazine reached 84.75%, while the conversions of reactants were also enhanced.

Synthesis of 2-Methylpyrazine on Ternary Oxide Catalysts

Synthesis of 2-methylpyrazine by cyclocondensation of ethylenediamine with 1,2-propylene glycol in the presence of zinc-molybdenum-chromium catalysts was studied.

Synthesis of 2-methyl pyrazine over zinc-modified ferrierite (FER) catalysts

Microporous ferrierite (FER) zeolites with different Si/Al ratios were prepared and modified with zinc. These were used as catalysts for the cyclization of ethylene diamine and propylene glycol to yield 2-methyl pyrazine (MP) in the temperature range 300–450 °C. Influence of reaction temperature, space velocity, reactant molar ratio and time on stream on the product pattern was investigated. The major product formed was MP. All these parameters were found to have significant influence on this reaction.

Binary oxide systems in catalytic synthesis of 2-methylpyrazine from 1,2-propylene glycol and ethylenediamine

A series of binary catalysts based on oxides of zinc and variable-valence metals were tested in synthesis of 2-methylpyrazine by catalytic dehydrocyclization of 1,2-propylene glycol with ethylenediamine.