- Development of a Synthesis of a 2,3-Disubstituted 4,7-Diazaindole Including Large-Scale Application of CH3Li/TiCl4-Mediated Methylation of an Enolizable Ketone
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The chemical development of a 2,3-disubstituted 4,7-diazaindole is described. The requisite tertiary carbinol substrate was prepared employing in situ-generated CH3TiCl3 as a chemoselective and preferred reagent compared to CH3MgX for methyl addition to an enolizable ketone. The 4,7-diazaindole ring system was efficiently assembled via an intramolecular Chichibabin transformation. The optimized processes were performed on pilot-plant scale to provide kilogram quantities of the target molecule.
- Weiberth, Franz J.,Gill, Harpal S.,Lee, George E.,Ngo, Duc P.,Shrimp, Frederick L.,Chen, Xuemin,D'Netto, Geoffrey,Jackson, Bryan R.,Jiang, Ying,Kumar, Narendra,Roberts, Frederick,Zlotnikov, Evgeny
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- Thermal Behavior Analysis of Two Synthesized Flavor Precursors of N-alkylpyrrole Derivatives
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To expand the library of pyrrole-containing flavor precursors, two new flavor precursors—methyl N-benzyl-2-methyl-5-formylpyrrole-3-carboxylate (NBMF) and methyl N-butyl-2-methyl-5-formylpyrrole-3-carboxylate (NUMF)—were synthesized by cyclization, oxidation, and alkylation reactions. Thermogravimetry (TG), differential scanning calorimeter, and pyrolysis–gas chromatography/mass spectrometry were utilized to analyze the thermal degradation behavior and thermal degradation products of NBMF and NUMF. The TG-DTG curve indicated that the maximum mass loss rates of NBMF and NUMF appear at 310 and 268°C, respectively. The largest peaks of NBMF and NUMF showed by the differential scanning calorimeter curve were 315 and 274°C, respectively. Pyrolysis–gas chromatography/mass spectrometry detected small molecule fragrance compounds appeared during thermal degradation, such as 2-methylpyrrole, 1-methylpyrrole-2-carboxylic acid methyl ester, limonene, and methyl formate. Finally, the thermal degradation mechanism of NBMF and NUMF was discussed, which provided a theoretical basis for their application in tobacco flavoring additives.
- Ai, Lvye,Liu, Mengzhen,Ji, Xiaoming,Lai, Miao,Zhao, Mingqin,Ren, Tianbao
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p. 2389 - 2397
(2019/08/01)
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- 1H-pyrrole-2,4-dicarbonyl-derivatives and their use as flavoring agents
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The present invention primarily relates to 1H-pyrrole-2,4-dicarbonyl-derivatives of Formula (I) wherein R1, R2, R3, Z. Z' and J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) or of a mixture of compounds of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- Imidazo[1,2-a]pyridine-ylmethyl-derivatives and their use as flavoring agents
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The present invention primarily relates to imidazo[1,2-a]pyridine-ylmethyl-derivatives of Formula (I) wherein R1, R2, X, W e J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- IMPROVED CHEMICAL SYNTHESIS OF DIAZAINDOLES BY CHICHIBABIN CYCLIZATION
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An improved synthesis method for making diazaindoles using a Chichibabin cyclization is disclosed. In particular, this method is useful for making the compound of Formula I.
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Page/Page column 6-7
(2010/10/03)
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- Supersonic jet studies of alkyl-substituted pyrazines and pyridines. Minimum energy conformations and torsional motion
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Conformational reference for methyl-, ethyl-, propyl-, and isoproply-substituted pyrazines and pyridines are determined by mass resolved excitation spectroscopy (MRES) and MOPAC 5/PM3 semiempirical calculations. The results of these studies suggest that the conformational behavior of alkyl-substituted pyrazines and pyridines is different from that of alkyl-subtituted benzenes. Based on the experimental and semiempirical theoretical results reported herein and published ab initio calculations, this difference can be attributed to a stabilizing interaction between an α-hydrogen atom of alkyl subsituted and the adjacent lone pair nonbonding electrons on the ring nitrogen atom.
- Seeman, Jeffey I.,Paine III, John B.,Secor, Henry V.,Im, Hoong-Sun,Bernstein
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p. 5269 - 5280
(2007/10/02)
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- Some Reactions of Mono Substituted Pyrazine Monoxides
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The reactions of the monoxides of propylpyrazine and phenylpyrazine with phosphoryl chloride or acetic anhydride were investigated.Except in the case of the reaction of 2-propylpyrazine 1-oxide with acetic anhydride, chlorination or acetoxylation occurred
- Ohta, Akihiro,Watanabe, Tokuhiro,Akita, Yasuo,Yoshida, Maki,Toda, Suzumi,et al.
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p. 1061 - 1067
(2007/10/02)
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