title: Ring contraction of 2,5-dihydrobenzo[f][1,2,5]thiadiazepine 1,1-dioxides: access to 4H-benzo[b][1,4]thiazine 1,1-dioxides.
abstract: We report an efficient synthesis of 4H-benzo[b][1,4]thiazine 1,1-dioxides via unprecedented ring contraction of 2,5-dihydrobenzo[f][1,2,5]thiadiazepine 1,1-dioxides under mild conditions involving carbon-sulfur bond formation. 2,5-Dihydrobenzo[f][1,2,5]thiadiazepine 1,1-dioxides are easily accessible from commercially available building blocks, including Fmoc-protected amino acids, 2-nitrobenzenesulfonyl chlorides, and bromo ketones. Benzothiazine 1,1-dioxides represent pharmacologically relevant derivatives with biological, medicinal, and industrial applications.
authors.affiliation: Department of Organic Chemistry, Institute of Molecular and Translational Medicine, Faculty of Science, Palacky University , 17. Listopadu 12, 771 46 Olomouc, Czech Republic.
authors.forename: Veronika
authors.initials: V
authors.lastname: Fülöpová
authors.forename: Anna
authors.initials: A
authors.lastname: Krchňáková
authors.forename: Eva
authors.initials: E
authors.lastname: Schütznerová
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Zajíček
authors.forename: Viktor
authors.initials: V
authors.lastname: Krchňák
mesh_terms: D001570:Benzodiazepinones / Q000737:chemistry*; D004852:Epoxy Compounds / Q000737:chemistry*; D009578:Nitrobenzenes / Q000737:chemistry*; D013829:Thiadiazines / Q000737:chemistry*; D013843:Thiazines / Q000737:chemistry*
chemical_list: D001570:Benzodiazepinones; D004852:Epoxy Compounds; D009578:Nitrobenzenes; D013829:Thiadiazines; D013843:Thiazines; C002732:2-nitrobenzenesulfenyl chloride