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Synthesis of 2-methylpyrazine by cyclocondensation of ethylenediamine with 1,2-propylene glycol in the presence of zinc3molybdenum3chromium catalysts was studied. 2-Methylpyrazine (MP) is used as an intermediate in synthesis of pyrazine-2-carboxamide (the basis of Pyrazinamide antituberculous drug [1]), but the existing procedures of its preparation are not perfect. MP can be prepared by the reaction of propylene oxide with ethylenediamine (EDA) in methanol in the presence of zinc3molybdenum3chromium oxide catalyst (yield 63%) [2]: g g H C 2 + HO O P 9 9 e Me Cat., , 7776 6 N N i

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“…The highest yield (75%) was obtained with the catalyst of the composition ZnO : MoO 3 = 1.0 : 0.3 (granule size 1.0 32.0 mm) [10].…”

Section: Homentioning

confidence: 96%

Synthesis of 2-Methylpyrazine on Ternary Oxide Catalysts

2005

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“…Catalytic systems based on zinc, 8 zinc-chromium, 9 copper-chromium 10 and Ag 11 were patented. Other catalysts such as ZnO-MoO 3 , ZnO-V 2 O 5 , Zn-WO 3 , 12 ZnO-MnSO 4 -H 3 PO 4 , 13 Ag-La-Zn/Al 2 O 3 , Ag-Pt/Al 2 O 3 , and Ag-Mg/Al 2 O 3 , 14 Pd-promoted ZnO/Zn-Cr-O catalysts, 15 zinc-modified ferrierite (FER), 16 H-ZSM-5, zinc-modified zeolite catalysts (including ZSM-5 and Beta) 17 were also used for synthesis of 2-methylpyrazine.…”

Section: Introductionmentioning

confidence: 99%

Catalytic synthesis of 2-methylpyrazine over Cr-promoted copper based catalyst via a cyclo-dehydrogenation reaction route

et al. 2010

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The cyclo-dehydrogenation of ethylene diamine and propylene glycol to 2-methylpyrazine was performed under the atmospheric conditions at 380°C. The Cr-promoted Cu-Zn/Al 2 O 3 catalysts were prepared by impregnation method and characterized by ICP-AES, N 2 adsorption/desorption, XRD, XPS, N 2 O chemisorption, TPR and NH 3 -TPD techniques. The amorphous chromium species existing in Cu-Zn-Cr/Al 2 O 3 catalyst enhanced the dispersion of active component Cu, promoted the reduction of catalyst. Furthermore, the catalytic performance was significantly improved. The acidity of the catalyst played an important role in increasing the 2-MP selectivity. To optimize the reaction parameters, influences of different chromium content, reaction temperature, liquid hourly space velocity (LHSV), reactants molar ratio and time on stream on the product pattern were studied. The results demonstrated that addition of chromium promoter revealed satisfying catalytic activity, stability and selectivity of 2-methylpyrazine.

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“…2-MP is the pivotal intermediate for obtaining 2-cyanopyrazine, which, when hydrolyzed, yields pyrazinamide, which is a well-known anti-tubercular drug. Previous reports have used palladized Zn−Cr oxide, ZSM-5, modified copper-chromite, binary catalyst based on oxides of zinc and variable-valence metals, zinc-modified ferrierite catalysts, zinc-modified zeolites, and CuO/ZnO/SiO 2 to synthesize 2-MP.…”

Section: Introductionmentioning

confidence: 99%

Vapor-Phase Catalytic Synthesis of 2-Methylpyrazine over a Nanocrystalline Ferrite Catalyst

Basak

Hardia

Saxena

et al. 2007

Ind. Eng. Chem. Res.

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Vapor-phase synthesis of 2-methylpyrazine (2-MP), from propylene glycol (PG) and ethylenediamine (ED), has been studied over ferrite catalysts in a temperature range of 523-773 K. The performance of MnFe 2 O 4 was observed to be better than that of Zn 1-x Mn x Fe 2 O 4 (x ) 0, 0.25, 0.5, 0.75). The reaction was determined to be almost stoichiometric, with an ∼98% conversion of PG. A maximum yield of 80% of 2-MP could be obtained at a temperature of 723 K, using a feed of ED, PG, and water (ED:PG:H 2 O molar ratio of 1:1:2) over MnFe 2 O 4 . The influence of reactant molar ratio, reaction temperature, weight hourly space velocity (WHSV), and time on stream (TOS) on the product yield has been studied. Catalyst characterization was made using X-ray diffraction (XRD), surface area measurement and ammonia desorption methods, scanning electron microscopy that has been coupled with energy-dispersive X-ray analysis (SEM-EDX), and Mo ¨ssbauer spectroscopy. Increasing the manganese content in Zn 1-x Mn x Fe 2 O 4 (x ) 0, 0.25, 0.5, 0.75, and 1) increases the paramagnetism of the samples, which seems to be responsible for enhanced activity of the catalysts as the value of x increases from 0 to 1.0. A tentative mechanism for the reaction has been proposed. It has been concluded that, similar to chromites, ferrites also can function as a dehydration/dehydrogenation catalyst.

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Cited by 4 publications

References 2 publications

Synthesis of 2-Methylpyrazine on Ternary Oxide Catalysts

Synthesis of 2-Methylpyrazine on Ternary Oxide Catalysts

Catalytic synthesis of 2-methylpyrazine over Cr-promoted copper based catalyst via a cyclo-dehydrogenation reaction route

Vapor-Phase Catalytic Synthesis of 2-Methylpyrazine over a Nanocrystalline Ferrite Catalyst

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