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Thermal Behavior Analysis of Two Synthesized Flavor Precursors of N ‐alkylpyrrole Derivatives
Author(s) -
Ai Lvye,
Liu Mengzhen,
Ji Xiaoming,
Lai Miao,
Zhao Mingqin,
Ren Tianbao
Publication year - 2019
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.3626
Subject(s) - chemistry , differential scanning calorimetry , mass spectrometry , pyrolysis , thermogravimetry , organic chemistry , decarboxylation , alkylation , flavor , chromatography , catalysis , inorganic chemistry , physics , thermodynamics , biochemistry
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.