کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
26894 | 43985 | 2013 | 6 صفحه PDF | دانلود رایگان |
• The 1-aryl-1,4-dihydropyrazines are unstable under irradiation with UV light.
• The 1-aryl-1,4-dihydropyrazines undergo photochemical ring contraction to 1-aryl-1H-imidazoles.
• The photochemical ring contraction is proposed to occur through a 6 π-electron cyclisation and a [1 + 2] cycloreversion.
The photochemical properties of 1-aryl-1,4-dihydropyrazines, including their UV–vis absorption, photostability and photoreaction, are investigated. The photostability of the 1-aryl-1,4-dihydropyrazines is studied in conventional solvents, and the results demonstrated that the 1-aryl-1,4-dihydropyrazines are unstable under irradiation with UV light. The 1-aryl-1,4-dihydropyrazines undergo photochemical ring contractions to 1-aryl-1H-imidazoles, as determined by 1H NMR, 13C NMR, HRMS, and single crystal X-ray diffraction analyses. The photochemical ring contraction is proposed to occur through a 6 π-electron cyclisation and a [1 + 2] cycloreversion.
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Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 267, 1 September 2013, Pages 49–54