title: A study of the electrospray ionisation and ion-trap fragmentation of [M - H](-) ions of new 3,5-disubstituted tetrahydro-2H-1,3,5-thiadiazin-2-thiones.
abstract: The electrospray ionisation (ESI) in negative mode of the pharmacologically significant 3,5-disubstituted tetrahydro-2H-1,3,5-thiadiazin-2-thiones, and their subsequent fragmentations using an ion-trap mass spectrometer, have been investigated. Experiments on sequential product ion fragmentations (MS(n)) were performed in order to elucidate the degradation pathways for these compounds. The data presented show that the fragmentation of the even-electron [M - H](-) ions could proceed through an internal nucleophilic substitution displacement. Decarboxylation and extrusion of carbon disulfide are other fragmentations observed.
authors.affiliation: Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense, E-28040 Madrid, Spain. rma@eucmos.sim.ucm.es
authors.forename: R
authors.initials: R
authors.lastname: Martínez-Alvarez
authors.forename: N
authors.initials: N
authors.lastname: Martín
authors.forename: C
authors.initials: C
authors.lastname: Seoane
authors.forename: M
authors.initials: M
authors.lastname: Suárez
authors.forename: R
authors.initials: R
authors.lastname: Pérez
authors.forename: H
authors.initials: H
authors.lastname: Rodríguez
authors.forename: N
authors.initials: N
authors.lastname: Kayali
mesh_terms: D003653:Decarboxylation; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013829:Thiadiazines / Q000737:chemistry*; D013871:Thiones / Q000737:chemistry*
chemical_list: D013829:Thiadiazines; D013871:Thiones