Studies on Fragmentation Regularity of 5-Methoxycarbonyl- 4-substituted-6-methyl-3,4-dihydropyrimidin-2(1H)-ones by Time-of-flight Mass Spectrometry  

作　　者：LIQian-rong SALEHIHojatollah YINHao GUOQing-xiang 

机构地区：[1]StructureResearchLaboratory [2]DepartmentofChemistry,UniversityofScienceandTechnologyofChina,Hefei230026,P.R.China

出　　处：《Chemical Research in Chinese Universities》2004年第6期729-733,共5页高等学校化学研究（英文版）

基　　金：National Natural Science Foundation of China(No.2 0 332 0 2 0 )

摘　　要：The electron impact time-of-flight(TOF) mass spectra of the title compounds were studied to establish their fragmentation processes. With the high resolution of the TOF instrument, the exact mass for each fragment was determined. These data were used to infer the molecular formulas and the elemental compositions for all the molecular ions and fragments through software interpretation. By further applying the fragmentation regularity, the majority of ions were fully assigned. The main fragmentation pathways of the title compounds include the formation of molecular ions by the loss of R 1 groups in the 4-position and the ester groups in the 5-position. The formed ion can be further fragmented by the elimination of MeOH.The electron impact time-of-flight(TOF) mass spectra of the title compounds were studied to establish their fragmentation processes. With the high resolution of the TOF instrument, the exact mass for each fragment was determined. These data were used to infer the molecular formulas and the elemental compositions for all the molecular ions and fragments through software interpretation. By further applying the fragmentation regularity, the majority of ions were fully assigned. The main fragmentation pathways of the title compounds include the formation of molecular ions by the loss of R 1 groups in the 4-position and the ester groups in the 5-position. The formed ion can be further fragmented by the elimination of MeOH.

关 键 词：3 4-Dihydropyrimidinone Time-of-flight mass spectrometry Electron impact 

分 类 号：O626.41[理学—有机化学] O657.63[理学—化学]