Synthesis and pyrolysis of two flavor precursors of oct-1-en-3-yl methylpyrazinecarboxylates
作者:Miao Lai、Xiaoming Ji、Tao Tao、Yuanyuan Shan、Pengfei Liu、Mingqin Zhao
DOI:10.1007/s10973-016-6083-5
日期:2017.6
To rich flavor additive species of pyrazines, two new compounds of 3,6-dimethyl-2,5-pyrazinedicarboxylic acid 1-octen-3-yl ester (DMPOE) and 3,5,6-trimethyl-2-pyrazinecarboxylic acid 1-octen-3-yl ester (TMPOE) were synthesized by KMnO4 oxidation, acylating chlorination and esterification reaction, in which tetramethylpyrazine and 1-octen-3-ol were used as initial materials. Thermogravimetry (TG), differential scanning calorimeter (DSC) and pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) were conducted to investigate the thermal degradation behaviors of DMPOE and TMPOE. TG–DTG results indicated that the T p of DMPOE and TMPOE with the largest mass loss rate was at 310 and 250 °C, respectively. The T peak of DMPOE and TMPOE showed by DSC curves was 301.8 and 260.0 °C, respectively. Py–GC/MS was performed to benefit the simulation of cigarette burning conditions, and the results indicated that DMPOE and TMPOE could release specific flavors of 1-octen-3-ol and diversified alkylpyrazines. Furthermore, the thermal degradation mechanisms of the flavor precursors of DMPOE and TMPOE were discussed. The study on the thermal behavior of these two methylpyrazinecarboxylates would provide theoretical basis for their application in tobacco.
为了丰富吡嗪类香料添加剂的种类,通过 KMnO4 氧化、酰化氯化和酰化氯化反应合成了 3,6-二甲基-2,5-吡嗪二羧酸 1-辛烯-3-基酯(DMPOE)和 3,5,6-三甲基-2-吡嗪二羧酸 1-辛烯-3-基酯(TMPOE)两种新化合物、以四甲基吡嗪和 1-辛烯-3-醇为初始原料,通过 KMnO4 氧化、酰化氯化和酯化反应合成了 3,6-二甲基-2,5-吡嗪二羧酸 1-辛烯-3-基酯(DMPOE)和 3,5,6-三甲基-2-吡嗪二羧酸 1-辛烯-3-基酯(TMPOE)。采用热重法(TG)、差示扫描量热仪(DSC)和热解-气相色谱/质谱法(Py-GC/MS)研究了 DMPOE 和 TMPOE 的热降解行为。TG-DTG结果表明,质量损失率最大的DMPOE和TMPOE的T峰分别位于310和250 ℃。DSC 曲线显示 DMPOE 和 TMPOE 的 T 峰分别为 301.8 和 260.0 ℃。为了模拟香烟燃烧条件,研究人员进行了 Py-GC/MS,结果表明 DMPOE 和 TMPOE 能释放出特定的 1-辛烯-3-醇和多种烷基吡嗪。此外,还讨论了 DMPOE 和 TMPOE 香味前体的热降解机制。对这两种甲基吡嗪羧酸盐热行为的研究将为它们在烟草中的应用提供理论依据。