Differentiation of Constitutional Isomer of 2,2a,3,4-Tetrahydro- 4-methyl-2a-phenyl-2- （thiophen-2-yl）- 1H-azeto [-2,1-d] [- 1,51benzothiazepin-1-one-5-oxide and Fragmentations of 2,3-Dihydro-2,4-diphenyl-1,5-benzothiazepine-l-oxide／- 1,1-d
摘要
Mass spectrometric behaviour of 2,2a, 3,4-tetrahydro-4-methyl-2a-phenyl-2- (thiophen-2-yl)- 1H-azeto [-2,1-d-J1-1,5-]benzothiazepin-l-one-5-oxide and 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-l-oxide/-1,1-dioxide have been studied with the aid of mass-analyzed ion kinetic energy spectrometry and accurate mass measurements under electron impact ionization. The monooxide derivatives showed a tendency to eliminate an alkene or an oxygen atom. 1H-Azeto[-2,1-d][1,5]benzothiazepin-1-one-5-oxide could also eliminate the thiophen- 2-ylketene molecule via a reverse [-2 q- 2 ~ cycloaddition. 2,3-Dihydro-2,4-diphenyl- 1,5-benzothiazepine-1-oxide/-1, 1-dioxide could eliminate SO2 or SO, respectively. The structure of 2,2a, 3, 4-tetrahydro-4-methyl-2a-phenyl-2- (thiophen-2-yl)-1H-azeto 1-2,1-d-] [1,5 -] benzothiazepin-1-one-5-oxide was identified on the basis of its fragmentation. The identification was supported by the fragmentations of model compound, 2,3-dihydro-2,4-diphenyl-1,5-benzothiazepine-1-oxide/-1,1-dioxide.