Whitehead, Calvert W. published the artcileReaction of saccharin with amines. N-Substituted-3-amino-1,2-benzisothiazole 1,1-dioxides, Computed Properties of 7668-28-2, the publication is Journal of Organic Chemistry (1960), 413-16, database is CAplus.
A number of CH:CH.CH:CH.C:C.C(NHR):N.SO2 (I) were prepared for pharmacol. evaluation as diuretic or hypoglycemic agents. Method A. Saccharin (II) (0.1 mole) added to excess alkyl- or aralkylamine boiling at at least 130° (after initial salt formation, the II dissolved), the solution refluxed 8 hrs., the excess amine removed in vacuo, the residue treated with Et2O, and the precipitate crystallized from EtOH or aqueous EtOH gave I. Method B. Pseudosaccharin chloride (Meadow and Reid, CA 37, 23609) (0.05-0.10 mole) added portionwise to 2 equivalents appropriate amine in dioxane, the mixture heated 1 hr. on a steam bath, the dioxane removed in vacuo, the residue dissolved in dilute EtOH, the solution treated with C (if necessary), the filtered solution concentrated, cooled, and the precipitate crystallized gave I. The following I were prepared (R, m.p., % yield, method given): Me, 292° (decomposition), 25, B; CH2CH2OH, 238°, 31, A; Pr, 215°, 61, B; iso-Am, 166°, 20, B; (CH2)3NMe2, 150° (C6H6), 41, A; 3-pyridylmethyl, 224° 55, A; cyclohexyl, 248°, 40, A; CH2Ph, 209°, 55, A; CH2CH2Ph, 244°, 52, A; CH2C6H4Me-p, 222°, 56, A; CH2C6H4Me-m, 214°, 55, A; CH2C6H4OMe-p, 209°, 46, A. II (0.10-0.20 mole) added to PhCl containing 1 equivalent appropriate amine, the mixture refluxed 8 hrs., the PhCl removed in vacuo, the residue acidified with dilute HCl, cooled, the precipitate collected, and recrystallized from dilute EtOH gave N-substituted-o-sulfamoylbenzamides, o-RHNO2SC6H4CONHR’ (III). N-Methylsaccharin (IV) (Rice and Pettit, CA 49, 12365b) (0.05-0.10 mole) added to excess alkyl- or aralkylamine boiling at at least 130°, the mixture refluxed 8 hrs., the excess amine removed in vacuo, the residue treated with dilute HCl, the solution cooled, the precipitate collected, and recrystallized from dilute EtOH gave N-substituted-o-methylsulfamoylbenzamides. The following III were prepared (R, R’, m.p., % yield given): H, cyclohexyl, 196°, 21; H, CH2Ph, 103°, 31; Me, cyclohexyl, 130°, 53; Me, CH2Ph, 105°, 33; H, CH2CH2Ph, 108°, 20; H, CH2C6H4OMe-p, 115°, 15; Me, CH2C6H4Me-p, 104°, 49. II (18 g.) and 5 g. 100% N2H4.H2O (V) in 250 ml. dioxane heated 5 hrs. on a steam bath, after the mixture became homogeneous the dioxane removed in vacuo, the crystalline residue collected, and the product crystallized from EtOH gave 16.5 g. o-H2NO2SC6H4CONHNH2 (VI), m. 180° (decomposition) (EtOH). IV (20 g.) added to 150 ml. dioxane followed by 5 g. 100% V, the mixture heated 4 hrs. on a steam bath, the dioxane removed in vacuo, the residue dissolved in EtOH, the solution filtered, the filtrate concentrated to smaller volume, cooled, and the resulting precipitate crystallized from EtOH gave 17 g. o-MeHNO2SC6H4CONHNH2 (VII), m. 140°. VI (5 g.) warmed on a steam bath with 40 ml. Ac2O until solution occurred, the solution allowed to stand overnight at room temperature, the excess Ac2O removed in vacuo, the residue dissolved in EtOH, the solution concentrated to smaller volume, cooled, and the precipitate (3 g.) recrystallized from EtOH gave N-acetylsaccharin, m. 191°. VII (5 g.) warmed on a steam bath with 35 ml. Ac2O, allowed to stand overnight at room temperature, worked up as above, and the product (3.5 g.) recrystallized from EtOH gave o-MeHNO2SC6H4CONHNHAc, m. 164°.
Journal of Organic Chemistry published new progress about 7668-28-2. 7668-28-2 belongs to isothiazole, auxiliary class Sulfamide,Amine,Benzothiazole, name is 3-Aminobenzo[d]isothiazole 1,1-dioxide, and the molecular formula is C12H14O, Computed Properties of 7668-28-2.
Referemce:
https://en.wikipedia.org/wiki/Isothiazole,
Isothiazole – ScienceDirect.com