1/7-2,1,4-Benzo thiadiazines

To a mixture of 3.0 grams of N,N -diacetyl-o-anilamide and 20 ml of acetic acid Is added a previously prepared solution of 1.5 grams of chlorine in 31 cc of acetic acid. The reaction mixture is allowed to stand at room temperature for 3 hours and is then evaporated to dryness on a steam bath under reduced pressure. The resulting solid residue is recrystallized from ethanol, yielding the intermediate N,N -diacetyl-2-sulfamyl-4-chloroaniline. The intermediate compound is fused in an oil bath at 250-260°C for 15 minutes, cooled and the product so obtained is crystallized from 80% ethanol yielding 3-methyl-7-chloro-1,2,4-benzo-thiadiazine-1,1-dioxide, MP 330°C. 

This intermediate is treated with an excess of 98% formic acid at steam bath temperature for 3 hours. Evaporation and dilution with water gives 7-sulfamyl-6-trifluoromethyl-1,2,4-benzo-thiadiazine-1,1 -dioxide, MP 304°C to 308°C. 

C15H9CI3N2O 13949-50-3) see Lorazepam 6-chloro-3-(chloromethyl)-3,4-dihydro-2/f-l,2,4-benzo-thiadiazine-7-sulfonamide 1,1-dioxide (CSH9CI2N3O4S2 1824-47-1) see Altizide 2-chloro-N-(2-chloro-6-methylphenyl)acetamide (C9H9CI2NO 6307-67-1) see Butanilicaine... 

U-Dihydro-7-sulfamyl-6"tr i -fluoromethy1-2H-l,2,U-benzo-thiadiazine 1,1-dioxide, AM5U... 

Tr if luoromethy 1-2JH-1,2, L-benzo-thiadiazine 1,1-dioxide, AL56 U-(Trifluoromethy )benzyl chloride, AL80... 

Proprietary Names. Navidrex. It is an ingredient of Trasidrex. 6-Chloro-3-cyclopentylmethyl- 3,4-dihydro-2//- 1,2,4-benzo-thiadiazine-7-sulphonamide 1,1 -dioxide Ci3H,8C1N304S2 = 379.9 CAS—742-20-1... 

The first synthesis of a 1 HA, 2,4-benzothiadiazine 1-oxide and simultaneously of the first cyclic sulfoximine were reported in 1964. 22 1 //-1,2,4-Benzothiadiazines were later prepared123 by reaction of S-(2-aminophenyl)sulfoximine 1 with cyanogen bromide to give 1//-1,2,4-thiadi-azin-3-amine 1-oxide 2a. Compounds 1 also react with phosgene to yield 1//-1,2,4-benzo-thiadiazin-3-amine 1-oxides 2b and c.123 An alternative route to 1 H-, 2,4-benzothiadiazine 1-oxides from sulfoximines and C-synthons has also been reported. 24 128... 

JCS(P1)447>. Related reactions are the oxidative cyclization of 3-amino-6-chloro-l-phenyl- , 2,4-benzothiadiazine 1-oxide (108 R =Ph, R = C1) to the 52 -l,2,4-triazolo[5,l-c][l,2,4]-benzo-thiadiazine 5-oxide (109) with triethyl orthoacetate in the presence of alcoholic ammonia and lead tetraacetate <86GEP3433307>, and the ring closures of the amines (108 R = Me, Ph R = H) to 5A -imidazo[l,2-c][l,2,4]benzothiadiazine S -oxides (110 R = Me, Ph) with ethyl bromopyruvate (Scheme 12) <88JMC1098>. 

Other than a detailed analysis of the N NMR spectrum of 3-phenylazo-li/-4,l,2-benzo-thiadiazine (21) (Section 6.17.7.2.2.2) no other N NMR spectral data for 1,3,4-oxadiazines or their thio-analogues appear to have been published. Nitrogen-15 chemical shift data (with respect to CH3NO2) for azo-compound (21) are appended to (21) <90MRC1027>. 

Benzyl-3, 4-dihydro-6-(trifluoromethyl)-2H, 1, 2, 4-benzo-thiadiazine-7 sulphonamide 1, 1-dioxide 2H, 1, 2, 4-Benzothiadiazine-7-sulphonamide, 3, 4-dihydro-3-(phenylmethyl)-6-(trifluoromethyl)-, 1,1-dioxide BR, USR, Int. R ... 

CsHCleN S] Cl ClsC N Cl Proton assignment based on McLachlan MO calcu Reduction of the appropriate chloride with sodium or dehydrogenation of the parent 1,2,4-benzo-thiadiazine with PbOj/ THF or benzene lations. EPR/ 300 2.0063 2.0065 2N 0.52 81 Marl... 

Y., Sekina, Y., and Hashimoto, M. Determination of 7-Chloro-3-(4-methyl-l-piperazinyl)-4H-1,2,4-benzo thiadiazine-1,1- dioxide (DU-717) in Plasma Using Electron-Capture Gas Chromatography J. Chromatogr. 160(1) 181-190 (1978) CA 90 80585r... 

The herbicide bentazon (3-isopropyl-2,l,3-benzo-thiadiazin-4-one-2,2-dioxide) is efficiently converted to give near quantitative yield of sulphur as sulphate ion and carbon as carbon dioxide dissolved and particulate organic carbon measurements also support nearly complete mineralization [35]. 

Theophylline-7-acetaldehyde and p-toluenesulfonic acid added to a suspension of 5-chloraniline-2,4-disulfonic acid diamide in dioxane, and refluxed 6-8 hrs. -> 3- (7-theophyllino) methyl -6- chloro-7- aminosulfonyl -3,4- dihydro -1,2,4-benzo-thiadiazine 1,1-dioxide. Y over 80%. F. e. s. J. Klosa, J. pr. 21, 176 (1963). 

A soln. of bromine in methanol added dropwise with stirring and cooling to a soln. of 5-nitro-2-p-chlorophenylthiobenzenesulfonamide in 5 NaOH 1-p-chlorophenyl-5-nitro-lH-l,3,2-benzodithiazole 3,3-dioxide. Y 92.1%.— The products may be regarded as cyclic sulfimides. F. e. and process modifications s. A. W. Wagner and R. Banholzer, B. 96, 1177 (1963) 3,4-dihydro-lH-l,2,4-benzo-thiadiazin-3-ones, in anhydrous medium, cf. A. 675, 189 (1964). 

Phenothiazines, benzo-l,2,4-thiadiazine 1,1-oxides, fluoroquinolones, nicotinic acid, and nitrofuran derivative as potentially dangerous photosensitizers 98MI11. 

For the benzo-fused derivative of the parent 1,2,6-thiadiazine 1,1-dioxide, the aromatic tautomer 125a (Scheme 35) was found to be the most stable (82JOC536). 

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