109-08-0Relevant articles and documents
Catalytic Synthesis Of Aziridine From 1,2-Diaminoethane
Anderson, A. A.,Simonyan, S. P.,Shimanskaya, M. V.
, p. 1134 - 1141 (1993)
The contact conversion of 1,2-diaminoethane over a tungsten trioxide catalyst at 240-580 deg C has been studied by an impulse chromatographic method.The basic reaction path under these conditions is unimolecular deaminocyclization to give aziridine (31-35percent).Piperazine and triethylenediamine, products of bi- and trimolecular deaminocyclization, are present as products.The deamination process is accompanied by coupled dehydrogenation and hydrogenolysis reactions.Addition of the acid anhydrides SiO2, P2O5 and B2O3 to the catalyst increases its activity but has onlyanegligible affect on the activation energy of the process.
Effective utilization of glycerol for the synthesis of 2-methylpyrazine over ZnO-ZnCr2O4 catalyst
Venugopal,Sarkari,Naveen Kumar,Kotesh Kumar,Syed John,Krishna Reddy,Hari Padmasri
, p. 387 - 393 (2014)
Bioglycerol an inevitable by-product in the production of biodiesel was effectively utilized for the synthesis of 2-methylpyrazine (2-MP) by vapour phase dehydrocyclization with ethylenediamine over ZnO-ZnCr2O 4(Zn-Cr-O) mixed oxides
Influence of Free Amino Acids, Oligopeptides, and Polypeptides on the Formation of Pyrazines in Maillard Model Systems
Scalone, Gustavo Luis Leonardo,Cucu, Tatiana,De Kimpe, Norbert,De Meulenaer, Bruno
, p. 5364 - 5372 (2015)
Pyrazines are specific Maillard reaction compounds known to contribute to the unique aroma of many products. Most studies concerning the generation of pyrazines in the Maillard reaction have focused on amino acids, while little information is available on the impact of peptides and proteins. The present study investigated the generation of pyrazines in model systems containing whey protein, hydrolyzed whey protein, amino acids, and glucose. The impact of thermal conditions, ratio of reagents, and water activity (aw) on pyrazine formation was measured by headspace solid-phase microextraction with gas chromatography/mass spectrometry (HS-SPME-GC/MS. The presence of oligopeptides from hydrolyzed whey protein contributed significantly to an increased amount of pyrazines, while in contrast free amino acids generated during protein hydrolysis contributed to a lesser extent. The generation of pyrazines was enhanced at low aw (0.33) and high temperatures (>120 °C). This study showed that the role of peptides in the generation of pyrazines in Maillard reaction systems has been dramatically underestimated.
Volatile Compounds Generated from Thermal Reaction of Methionine and Methionine Sulfoxide with or without Glucose
Yu, Tung-Hsi,Ho, Chi-Tang
, p. 1641 - 1646 (1995)
Methionine and methionine sulfoxide were mixed with or without glucose in distilled water, individually.These solutions were heated in closed sample cylinders at 180 deg C for 1 h.The volatile compounds generated were extracted using methylene chloride and analyzed by GC and GC-MS.Pyrazine compounds, especially 2,5-dimethyl-, 2-ethyl-5-methyl-, trimethyl-, and methylpyrazines were the predominant compounds among those generated from thermal interactions of glucose and methionine or methionine sulfoxide.The formation of methional or those compounds derived for methional was found to be more favorable from the thermal degradation of methionine, whereas the formation of dimethyl polysulfides, especially dimethyl disulfide and dimethyl trisulfide, was found to be more favorable from the thermal degradation of methionine sulfoxide.Glucose was found to have a catalytic effect on the formation of volatile compounds from the thermal degradation of methionine or methionine sulfoxide.Keywords: Methionine; methionine sulfoxide; methional; methyl sulfides; volatiles
Binary oxide systems in catalytic synthesis of 2-methylpyrazine from 1,2-propylene glycol and ethylenediamine
Balpanov,Krichevskii,Kagarlitskii
, p. 2125 - 2127 (2001)
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.
Catalytic synthesis of 2-methylpyrazine over Cr-promoted copper based catalyst via a cyclo-dehydrogenation reaction route
Jing, Fangli,Zhang, Yuanyuan,Luo, Shizhong,Chu, Wei,Zhang, Hui,Shi, Xinyu
, p. 621 - 630 (2010)
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 2O 3 catalysts were prepared by impregnation method and characterized by ICP-AES, N 2 adsorption/desorption, XRD, XPS, N 2O chemisorption, TPR and NH3-TPD techniques. The amorphous chromium species existing in Cu-Zn-Cr/Al 2O 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. Indian Academy of Sciences.
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
Teodorescu,Slabu,Pavel,Z?voianu
, (2020)
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).
Degradation Products Fromed from Glucosamine in Water
Shu, Chi-Kuen
, p. 1129 - 1131 (1998)
An aqueous solution of glucosamine hydrochloride was heated to 150 °C for 5 min under different pH conditions. The reaction product mixture obtained was analyzed by GC/MS. It was found that the major products formed were furfurals, especially at pH = 4 and 7. At pH = 8.5, additional flavor components were generated, including pyrazines, 3-hydroxypyridines, pyrrole-2-carboxaldehyde, furans, acetol, and several other compounds. Of the components identified, it is worthwhile to note the formation of pyrazine and methylpyrazine as major components at pH = 8.5. It is proposed that a retro-aldol condensation plays an important role in the formation of the intermediates, α-aminoacetaldehyde (I) and α-amino propanal (II). As a result, self-condensation of I generates pyrazine and combination of I and II generates methylpyrazine. In addition, it is also interesting to note the formation of 3-hydroxypyridines and pyrrole-2-carboxaldehyde. It is suggested that both groups of compounds are derived from furfurals. As the ammonia is liberated from glucosamine, it initiates the ring-opening of furfurals to form 5-amino-2-keto-3-pentenals. Intramolecular condensations of these intermediates between the amino group and the carbonyl groups lead to the formation of 3-hydroxypyridines and pyrrole-2-carboxalhyde.
Kinetics and thermal degradation of the fructose-methionine Amadori intermediates. GC-MS/SPECMA data bank identification of volatile aroma compounds
Vernin, Gaston,Metzger, Jacques,Boniface, Christian,Murello, Marie-Helene,Siouffi, Antoine,et al.
, p. 15 - 30 (1992)
Fructose-methionine Amadori intermediates, prepared from D-glucose and L-methionine, were purified by semi-preparative HPLC.Structural elucidation was achieved by 13C-NMR and mass spectrometry in the FAB+ and FAB- modes.Constant rates of formation of glucosylamine and the Amadori intermediate, and their thermal degradation into reductones and methionine as well as into diglucosylamine, were observed.Thermal degradation of the Amadori intermediate gives not only the well-known degradation products of the sugar moiety and methional (from the Strecker degradation of methionine), but also several heterocyclic compounds (pyridines, pyrazines, pyrroles, and furans).Some of them contain a methylthiopropyl group in their side chain.These new compounds were identified by the fragmentation rules and Kovats additive properties.Out of the 80 compounds isolated, ca. 70 were identified.
Vapor phase synthesis of methylpyrazine using aqueous glycerol and ethylenediamine over ZnCr2O4 catalyst: Elucidation of reaction mechanism
Sarkari, Reema,Anjaneyulu, Chatla,Krishna, Vankudoth,Kishore, Ramineni,Sudhakar, Medak,Venugopal, Akula
, p. 1067 - 1070 (2011)
A novel method has been developed for the synthesis of methylpyrazine (MP) by using aqueous glycerol and ethylenediamine (EDA) over Zn-Cr catalyst derived from hydrotalcite precursors. The X-ray diffraction analysis of the oven-dried Zn-Cr samples synthesized at various pH ranging from 7 to 11 showed hydrotalcite phase whereas the calcined catalysts displayed ZnO and ZnCr2O 4 phases. The cyclisation activity of Zn-Cr catalyst prepared at pH ～ 9 demonstrated 99.4% conversion of EDA and 94% of glycerol with ～ 72% selectivity to MP at a reaction temperature of 400 °C. This process demonstrates direct utilization of bio-glycerol for the synthesis of MP.
