Fast-atom bombardment mass spectrometric studies of trisubstituted 3a,4,5,11-tetrahydro- 1,2,4-oxadiazolo[5,4-d][1,5]benzothiazepines

Electron impact mass spectral fragmentation of 3a,5-disubstituted 1,3-diphenyl-3a,4,5,6-tetra-hydro-3H-1,2,4-triazolo[4,3-a][1,5]benzo-diazepines

“…The e' ions could further lose NH 2 to produce stable tetracyclic 1,3-diphenyl-1,2,4-triazolo [4,3d]phenanthridine ions (f). This behavior is similar to that reported in our previous papers [14][15][16] for related compounds. The f ions could produce 1-phenyldiazirino [2,3-d]phenanthridine ions (1) by loss of benzonitrile PhCN, or undergo a reverse [2 3] cycloaddition to give phenanthridine ions (m) and N-phenylbenzonitrile imine (PhC = N -N À -Ph) ions (h).…”

“…[5][6][7][8] During the past decade we have performed detailed investigations on the synthesis, stereochemistry and spectral properties of a series of tricyclic benzodiazepine derivatives. [9][10][11][12][13][14][15][16][17][18] As a continuation of our work on the benzodiazepine tricyclic derivatives, we synthesized a series of new 1,3,3a,5-tetraaryl-3a,4,5,6-tetrahydro-3H-1,2,4-triazolo [4,3-a] [1,5]benzodiazepines with potential antidepressant, 19 antianxiety, 20 diuretic and natriuretic activities. 21 Herein we report detailed studies of the fragmentation mechanisms under electron impact (EI) ionization conditions of six 3a,5disubstituted 1,3-diphenyl-3a,4,5,6-tetrahydro-3H-1,2,4-triazolo[4,3-a] [1,5]benzodiazepines.…”

Electron impact mass spectral studies of 2a,4-disubstituted 2-phthalimido-2,2a,3,4-tetrahydro-1H-azeto[2,1-d][1,5]benzothiazepin-1-ones

“…A characteristic fragmentation mechanism of the sevenmembered heterocyclic system involves loss of a neutral moiety [R 1 -CH=CH 2 ] from the benzothiazepine ring to produce some important ions with appreciable relative abundances. [14][15][16][17]22 However, the benzothiazepine ring in the title compounds showed better stability than others reported previously. [14][15][16][17]22 They could not eliminate directly a neutral moiety R 1 -CH=CH 2 from the benzothiazepine rings before they had lost other neutral fragments.…”

“…[5][6][7][8] Recently, we performed detailed investigations on the synthesis, stereochemistry and spectral properties of a series of tricyclic benzodiazepine derivatives. [9][10][11][12][13][14][15][16][17][18] Most important antibiotics possess a representative structure of a b-lactamfused five-or six-membered heterocyclic ring containing nitrogen and sulfur atoms. [19][20][21] As a continuation of our studies on tricyclic benzothiazepine derivatives, herein we report detailed studies of the fragmentation mechanisms under electron impact (EI) ionization conditions of seven 2a,4-disubstituted 2-phthalimido-2,2a,3,4-tetrahydro-1H-azeto[2,1-d] [1,5]benzothiazepin-1-ones, containing a b-lactam-fused dihydrobenzothiazepine seven-membered heterocyclic ring.…”

Mass Spectrometric Fragmentation of 2a,4-Disubstituted 2,2a,3,4-Tetrahydro-2-phenyl-1H-azeto[2,1-d]- [1,5]benzothiazepin-1-ones Under Electron Impact Ionization Conditions and Comparison with their 2-Heteroatom Substituted Analogues

“…[15][16][17][18][26][27][28]30 However, the benzothiazepine ring in the title compounds showed better stability than others reported previously. [15][16][17][18][26][27][28]30 They could not eliminate directly a neutral moiety R 1 -CH CH 2 from the benzothiazepine rings before they had lost a phenylketene fragment.…”