title: N-(X-chlorophenyl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide (with X = 2 and 4).
abstract: The structures of N-(2-chlorophenyl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide and N-(4-chlorophenyl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide, both C16H13ClN2O4S, are stabilized by extensive intramolecular hydrogen bonds. The 4-chloro derivative forms dimeric pairs of molecules lying about inversion centres as a result of intermolecular N-H...O hydrogen bonds, forming 14-membered rings representing an R2(2)(14) motif; the 2-chloro derivative is devoid of any such intermolecular hydrogen bonds. The heterocyclic thiazine rings in both structures adopt half-chair conformations.
authors.affiliation: Department of Chemistry, University of Sargodha, Sargodha, Pakistan.
authors.forename: Waseeq Ahmad
authors.initials: WA
authors.lastname: Siddiqui
authors.forename: Saeed
authors.initials: S
authors.lastname: Ahmad
authors.forename: Muhammad Ilyas
authors.initials: MI
authors.lastname: Tariq
authors.forename: Hamid Latif
authors.initials: HL
authors.lastname: Siddiqui
authors.forename: Masood
authors.initials: M
authors.lastname: Parvez
mesh_terms: D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D013843:Thiazines / Q000737:chemistry*
chemical_list: D006575:Heterocyclic Compounds, 3-Ring; D006843:Hydrocarbons, Chlorinated; C527970:N-(2-chlorophenyl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide; C527971:N-(4-chlorophenyl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide; D013843:Thiazines