Pyrolysis Analysis of Novel Latent Fragrant Compounds -2,3-Pyrazinedicarboxlic Acid Menthyl Ester

In order to develop the heat-release type of tobacco flavor additives, 2, 3-pyrazinedicarboxylic acid menthyl ester was prepared through esterification using 2, 3-pyrazinedicarboxylic acid and menthol as raw material, N, N′-dicyclohexylcarbodiimide (DCC) as condensing agent and 4-dimethylaminopyridine (DMAP) as catalyst. The structure of the target compound was characterized by X-ray single crystal diffraction, ¹H NMR, ¹³C NMR, IR and HRMS. Combined with simultaneous thermal stability analysis, the fragmentation products of the target compound were qualitatively and semi-quantitatively analyzed by on-line pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) at three temperature levels of 300, 600 and 900 ℃, respectively. The possible fragmentation mechanism was initially speculated. The results show that the sample target compound is nearly decomposed in the range of major thermal weight loss occurred from 268.5 ℃ to 334.9 ℃. The melting temperature is 140.9 ℃, and the pyrolysis temperature is 315.9 ℃. 46 kinds of fragmentation products are identified, mainly including 3-p-menthene, menthol and pyrazine, which are aroma components and play an important role in tobacco flavor. This method is an accurate and quick way to isolate and identify the fragmentation products of hot food spices additives, which can provide a reliable theoretical reference for the additives in application of tobacco flavoring.