Benzisothiazolin-3-one

The same treatment of A-methyl(<9-methyl)arenesulfonamide (38) generates the corresponding 1,2-benzisothiazoline-3-one 1,1,-dioxide (A-methylsaccharins) (39), through triple 1,5-H shift and hydrolysis of the formed A-methyl(<9-triiodomethyl)ar-enesulfonamides [55]. This method is very useful, since biologically attractive 1,2-benzisothiazoline-3-one 1,1-dioxides bearing various kinds of substituents on the aromatic ring can be prepared under neutral conditions. 

The 2-(3-oxo-l,2-benzisothiazolinyl) group in 2-mercaptobenzoates 7 could easily be replaced with a variety of amines to give TV-substituted 2-sulfenamoylbenzoates 8 or TV-substituted 1,2-benzisothiazolin-3-ones 9 in good yield <02T3779>. 

H(55)1759>. N-Unsubstituted l,2-benzisothiazolin-3-ones 344 (R = H R = H, Cl, OMe R = H, Cl, OMe) can be prepared in a chlorine-free synthesis by cyclization of 2-sulfenamoylbenzoates 342 (R = OR, R = NH2) which are prepared by amination of thiosalicylates with hydroxylamine-O-sulfonic acid. N-Substituted sulfenamoylbenzoates, prepared by transamination with different amines, can be cyclized to N-substituted 1,2-benzisothiazolin-3-one 344 (R = PhCH2,/ -MeOC6H4CH2,/>-ClC6H4CH2) <2003H(60)1855>. 

Benzisothiazolin-3-one 1,1-dioxide benzoic sulfimide benzosulfimide l,2-dihydro-2-ketobenzisosulfonazole 2,3-dihydro-3-oxobenzisosulfonazole E954 Garantose gluside Hermesetas sacarina saccharin insoluble o-sulfobenzimide o-sulfobenzoic acid imide. 

Benzisothiazolin-3-one 1,1-dioxide, sodium salt Crystal-lose E954 sodium o-benzosulfimide soluble gluside soluble saccharin sucaryl sodium. 

The Su rez modification of the HLF reaction was the basis of the new synthetic method developed by H. Togo et al. The authors prepared A/-alkyl-1,2-benzisothiazoline-3-one-1,1-dioxides (A/-alkylsaccharins) from A/-alkyl(o-methyl)-arenesulfonamides using (diacetoxyiodo)arenes in the presence of iodine via sulfonamidyl radicals. The transformations did not work in the dark, indicating the radical nature of the reaction. The yields varied from moderate to excellent and the nature of the aromatic substituents on both the substrate and the (diacetoxyiodo)arenes were important. It should be noted that the oxygen atom at the C3 position most likely arises from the hydrolysis of a C3 diiodo intermediate (not isolated). 

Katohgi, M., Togo, H., Yamaguchi, K., Yokoyama, M. New synthetic method to 1,2-benzisothiazoline-3-one-1,1-dioxides and 1,2-benzisothiazoline-3-one-1-oxides from N-alkyl(o-methyl)arenesulfonamides. Tetrahedron 1999, 55,14885-14900. 

The advantage of using the thermolysis of 2-(benzylsulfinyl)benzamide or treatment of the corresponding /-butylsulfinyl compound with trichloroacetic acid for the preparation of 1,2-benzisothiazolin-3-ones is that the conditions are milder than those previously reported for the cyclization <92TL153> (see Section 3.05.9.1.1). 

Synthesis of 1,2-Benzisothiazolin-3-ones from Thermal Decomposition of H-Substituted 2-(Methylthio)benzamides. The compounds 2-MeSC6H4CON-(Bu )OCOR (R = Ph or 4-MeCeH4) are prepared by acylating Bu NHOCOR with 2-MeSC6H4COCl in the presence of pyridine. Compound (56 R = Me,... 

Ammonium 1.2-benzisothiazolin-3one 1,1-dioxide Ammonium 0-benzosulflmide Ammonium saccharin 1,2-Benzisothiazolin-3-one, 1,1-dioxide, ammonium salt Daramin EINECS 223971-8 Saccharin ammonium Saccharinale ammonium. 

U093. . Benzenamine, N,N -dimethyl-4-(phenylazo)H202. . 1,2-Benzisothiazolin-3-one, 1,1-... 

Synthesis of 1,2-Benzisothiazolin-3-ones (1,1-dioxides).-from 2-(methylsulphinyl)benzaniides or N-t2-(methylthio)benzovl]-N-alkylhvdroxylamines and SOCl. Compounds (28 R=alkyl,cycloalkyl, benzyl,Ph,Ar) or (29 R=alkyl) react with SOClg to give 2-substituted 1,2-benzisothiazol-3(2H)-ones (30) nearly quantitatively. In contrast, chlorinated anilides are the major products from S0C1- and (29 R=Ar). Saccharin and analogues are pre-pared by a variety of methods ... 

Reactions of 1,2-Benzisothiazolin-3-ones. - with activated methylene compounds. N-methyl-saccharin reacts with CICHgCOOCHgCHgOMe and derivatives to form (31 R=C1,Br,I,R1=C 1 , MeOCHgCHgO). 

N-Substitution of 1,2-Benzisothiazolin-3-ones. - Saccharin Na salt reacts with various bromoalkanes, bromoketones, and bromo-alkanoic acids (esters) to form N-substituted derivatives [35 ... 

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