Collection of ion-trap mass spectra of sulfonylurea pyrolysis products
作者:Guido C. Galletti、Giovanni Dinelli、Giuseppe Chiavari
DOI:10.1002/jms.1190300216
日期:1995.2
The pyrograms of 14 sulfonylureas, i.e. herbicides characterized by high biological activity and low application dose are discussed and the mass spectra of over 30 relevant pyrolysis products as obtained with a heated filament pyrolyzer interfaced to a capillary gas chromatograph/ion-trap detector mass spectrometer are presented. Such a data compilation is useful for diagnostic purposes for both intact suflfonylureas and their metabolites after degradation in soil, because metabolites and pyrolysis products are often identical and most of their mass spectra are lacking in commercially available mass spectral libraries. The performance of the ion-trap detector based on the quality of the mass spectra is briefly discussed.
Molecular structure and infrared spectra of the monomeric 3-(methoxy)-1,2-benzisothiazole 1,1-dioxide (methyl pseudosaccharyl ether)
作者:Agnieszka Kaczor、Rui Almeida、Andrea Gómez-Zavaglia、Maria de Lurdes S. Cristiano、Rui Fausto
DOI:10.1016/j.molstruc.2007.06.004
日期:2008.3
exhibit considerably short (1.320 A) and long (1.442 A) (N )CO and (H 3 )CO bonds, respectively, and a hybridization of the central oxygen atom close to sp 2 (the COC angle is predicted to be ca. 117°). This COC bonding pattern fits the well-known high reactivity of MBID upon thermal rearrangement, which has been shown to result in easy selective [1,3′]-isomerization of the compound.
Abstract The thermal Chapman-type rearrangement of the pseudosaccharin 3-(methoxy)-1,2-benzisothiazole 1,1-dioxide (MBID) into 2-methyl-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (MBIOD) was investigated on the basis of computational models and knowledge of the structure of the reactant and product in the isolated and solid phases. X-ray diffraction was used to obtain the structure of the substrate in
Process for the preparation of a 3-hydroxy-2,3-dihydrobenzisothiazole 1,1-dioxide and the use of this compound as a biocide and for preparing an ortho-sulphobenzimide
申请人:AKZO N.V.
公开号:EP0162494A1
公开(公告)日:1985-11-27
The invention relates to a one-step process for the preparation of a 3-hydroxy-2,3-dihydrobenzisothiazole-1,1-dioxide in a high yield by oxidation of an ortho-toluene sulphonamide in the liquid phase using molecular oxygen and/or ozone in the presence of one or more catalysts.
The oxidation is terminated before 50% of the starting material has been convented into resultant oxidation products from the 3-hydroxy-2,3-dihydrobenzisothiazole-1,1-dioxide and into other oxidation products. It is preferred that the reaction should be carried out in acetic acid or free of solvent using cobalt and/or manganese salts as a catalyst.
The benzisothiazole-1,1-dioxides can be oxidized to an ortho-sulphobenzimide. In this way saccharin can be prepared. The bezisothiazole-1,1-dio×ides also display biocidal activity.