- New ring systems from 1,2-benzisothiazole-1,1-dioxides and related compounds
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Ring-expansions and ring-annulations based on 3-substituted 1,2-benzisothiazole-1,1-dioxides have lead to a variety of novel heterocyclic systems. The reaction of 3-substituted (1H)-1-isoindoles with 1-diethylamino-1-propyne has also resulted in new, ring-expanded molecules in good to modest yields.
- Abramovitch, Rudolph A.,Shinkai, Ichiro,Mavunkel,More,O'Connor, Sean,Ooi, Gino H.,Pennington, William T.,Srinivasan,Stowers, James R.
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- Reaction of orthto-lithiated N-methylbenzamide with 1,2-Diketones: A novel highly efficient route to N-methylisoquinolin-1-one
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1,2-Diketones were found to react with ortho-lithlated N-methylbenzamide to give diols 4a-g in 59-80% yields. Reaction of diols 4a-g with the system Me3SiCl/Nal in MeCN furnished N-methylisoquinolin-1-ones in 84-92% yields.
- Kiselyov, Alexander S.
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- Decarbonylative C-C bond-forming reactions of saccharins by nickel catalysis: Homocoupling and cycloaddition
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Decarbonylation of saccharins by nickel catalysis enables two kinds of C-C bond-forming reactions; homocoupling of saccharins to form biaryls and cycloaddition with alkynes to form benzosultams. The former represents the first reported nickel-catalyzed decarbonylative C-C homocoupling reaction, whereas the latter constitutes a powerful method to pharmaceutically relevant benzosultams. The reactions proceed with good functional-group tolerance and excellent regioselectivity.
- Mi, Pengbing,Liao, Peiqiu,Tu, Tao,Bi, Xihe
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- Direct preparation of saccharin skeletons from N-methyl(o-methyl)arenesulfonamides with (diacetoxyiodo)arenes
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Various N-methylsaccharins were easily prepared in moderate to good yields by the reaction of N-methyl(o-methyl)arenesulfonamides with (diacetoxyiodo)arene in the presence of iodine under irradiation with a tungsten lamp. The present method is very useful for the direct preparation of saccharins with N-methyl(o-methyl)arenesulfonamides containing various substituents on the aromatic ring.
- Togo, Hideo,Katohgi, Masashi,Yokoyama, Masataka
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- The Chapman-type rearrangement in pseudosaccharins: The case of 3-(methoxy)-1,2-benzisothiazole 1,1-dioxide
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The thermal Chapman-type rearrangement of the pseudosaccharin 3-(methoxy)-1,2-benzisothiazole 1,1-dioxide (MBID) into 2-methyl-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (MBIOD) was investigated on the basis of computational models and knowledge of the structure of the reactant and product in the isolated and solid phases. X-ray diffraction was used to obtain the structure of the substrate in the crystalline phase, providing fundamental structural data for the development of the theoretical models used to investigate the reaction mechanism in the condensed phase. The intra- and different intermolecular mechanisms were compared on energetic grounds, based on the various developed theoretical models of the rearrangement reactions. The energetic preference (ca. 3.2 kJ mol-1, B3LYP/6-31+G(d,p)) of inter- over intramolecular transfer of the methyl group is predicted for the quasi-simultaneous transfer of the methyl groups model, explaining the potential of MBID towards [1,3′]-isomerization to MBIOD in the condensed phases. The predicted lower energy of MBIOD relative to MBID (ca. 60 kJ mol-1), due to the lower steric hindrance in the MBIOD molecule, acts as a molecular motor for the observed thermal rearrangement.
- Kaczor,Proniewicz,Almeida,Gómez-Zavaglia,Cristiano,Matos Beja,Ramos Silva,Fausto
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- First observation of Chapman rearrangement of a pseudosaccharyl ether in the solid state: the thermal isomerization of 3-(methoxy)-1,2-benzisothiazole 1,1-dioxide revisited
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3-(Methoxy)-1,2-benzisothiazole 1,1-dioxide, a pseudosaccharyl ether, was long ago known to undergo a thermal Chapman-like [1,3′]-isomerization to the corresponding N-methyl pseudosaccharin at temperatures above its melting point (ca. 184 °C) [Hettler H., Tetrahedron Lett. 1968, 15, 1793]. In the present study, it is shown that this rearrangement can also take place in the solid state, at temperatures as low as 150 °C. This was the first observation of a Chapman-like [1,3′]-isomerization in pseudosaccharyl ethers in the solid state. The study has been carried out by a multidisciplinary approach using temperature dependent infrared spectroscopy, differential scanning calorimetry (DSC), and polarized light thermomicroscopy, complemented by theoretical methods.
- Almeida,Gómez-Zavaglia,Kaczor,Cristiano,Eusébio,Maria,Fausto
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- MODIFIED PROTEINS AND PROTEIN DEGRADERS
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Provided herein are compounds, pharmaceutical compositions, and methods for binding or degrading target proteins. Further provided herein are compounds having a DNA damage-binding protein 1 (DDB1) binding moiety. Some such embodiments include a linker. Some such embodiments include a target protein binding moiety. Further provided herein are ligand-DDB1 complexes. Further provided herein are in vivo modified DDB1 proteins.
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Paragraph 00727-00729
(2021/12/08)
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- Synthetic method for preparing saccharin (by machine translation)
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1,2 - Benzisothiazol -3 - ketone compounds are subjected to an oxidation reaction with an oxidizing agent, and an oxidizing agent oxidizes thioether of 1,2 - benzisothiazol -3 -one compound to thioamide to obtain the O-benzoyl sulfamide compound. Compared with the traditional production technology of saccharin, the saccharin synthesis method has the advantages of simple process, low cost, high separation efficiency, low pollution and the like, and accords with the green chemistry. (by machine translation)
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Paragraph 0077-0078
(2020/07/02)
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- Bu4NI-Catalyzed, Radical-Induced Regioselective N-Alkylations and Arylations of Tetrazoles Using Organic Peroxides/Peresters
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Bu4NI-catalyzed regioselective N2-methylation, N2-Alkylation, and N2-Arylation of tetrazoles have been achieved using tert-butyl hydroperoxide (TBHP) as the methyl source, alkyl diacyl peroxides as the primary alkyl source, alkyl peresters as the secondary and tertiary alkyl sources, and aryl diacyl peroxides as the arylating source. These reactions proceed without pre-functionalization of tetrazole and in the absence of any metal catalysts. Here, peroxides serve the dual role of oxidants as well as alkylating or arylating agents. Based on DFT calculations, it was found that spin density, transition-state barriers (kinetic control), and thermodynamic stability of the products (thermodynamic control) play essential roles in the observed regioselectivity during N-Alkylation. This radical-mediated process is amenable to a broad range of substrates and provides products in moderate to good yields.
- Ghosh, Subhendu,Mir, Bilal Ahmad,Patel, Bhisma K.,Rajamanickam, Suresh,Sah, Chitranjan,Sethi, Garima,Venkataramani, Sugumar,Yadav, Vinita
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p. 2118 - 2141
(2020/03/13)
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- Synthesis of (e)-n-substituted 1,2-benzothiazol-3(2h)-imine 1,1-dioxide derivatives from secondary benzenesulfonamides and isothiocyanates
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A new and simple method for the preparation of (E)-N-substituted 1,2-benzothiazol-3(2H)-imine 1,1-dioxide derivatives has been developed. 2,N-Dilithiobenzenesulfonamides, generated by the treatment of secondary benzenesulfonamides with two equivalents of butyllithium, react with isothiocyanates to afford the corresponding 2-(aminosulfonyl)benzothioamides, which undergo ring closure with a formal elimination of hydrogen sulfide on treatment with thionyl chloride in the presence of two equivalents of pyridine to provide the desired products. Acid hydrolysis of some of these products leads to the formation of N-substituted saccharins.
- Kobayashi, Kazuhiro,Fujiwara, Daiki
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p. 1275 - 1288
(2018/08/07)
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- Carbodiimide insertion into sulfonimides: one-step route to azepine derivatives via a two-atom saccharin ring expansion
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A previously unknown insertion of carbodiimides into sulfonimides enables the first one-step, two-atom expansion of the saccharin 5-membered ring into a 7-membered benzo[1,2,4]thiadiazepine, and a two-atom chain extension of a non-cyclic sulfonimide. This reaction is enhanced by copper salts, which allow it to be conducted mechanochemically, in a solvent-free manner.
- Tan, Davin,Fri??i?, Tomislav
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supporting information
p. 901 - 904
(2017/01/17)
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- Regioselective alkylation of saccharin with alcohols under Mitsunobu conditions
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The regioselective Mitsunobu alkylation of saccharin with various alcohols has been examined. The N/O-alkylation is dependent on the steric hindrance of the alcohols, that is, less sterically hindered alcohol preferentially afford N-alkylated saccharin an
- Wang, Xiaolong,Ma, Yanying,Ju, Tingting
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p. 417 - 419
(2013/09/12)
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- Studies of silyl-transfer photochemical reactions of N-[(trimethylsilyl) alkyl]saccharins
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Photochemical studies of N-[(trimethylsilyl)alkyl]saccharins were carried out to investigate their photochemical behavior. Depending on the nature of the substrate and the solvent system employed, reactions of these substances can take place by either SET-promoted silyl migration from carbon to either the amide carbonyl or sulfonyl oxygen or by a N-S homolysis route. The results of the current studies show that an azomethine ylide, arising from a SET-promoted silyl migration pathway, is generated in photoreactions of N-[(trimethylsilyl) methyl]saccharin and this intermediate reacts to give various photoproducts depending on the conditions employed. In addition, irradiation of N-[(trimethylsily)ethyl]saccharin produces an excited state that reacts through two pathways, the relative importance is governed by solvent polarity and protic nature. Finally, photoirradiation of N-[(trimethylsilyl)propyl]saccharin in a highly polar solvent system comprised of 35% aqueous MeOH gives rise to formation of a tricyclic pyrrolizidine and saccharin that generated via competitive SET-promoted silyl transfer and γ-hydrogen abstraction pathways.
- Cho, Dae Won,Oh, Sun Wha,Kim, Dong Uk,Park, Hea Jung,Xue, Jin Ying,Yoon, Ung Chan,Mariano, Patrick S.
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experimental part
p. 2453 - 2458
(2010/11/17)
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- A novel photoisomerzation of 1,2-benzothiazine 1,1-dioxides to 1,3-benzothiazine 1,1-dioxides
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(Chemical Equation Presented) A novel facile photoconversion of 4-hydroxy-1,2-bezothiazine 1,1-dioxides (3a-e) into 4-oxo-1,3-2H-benzothiazine 1,1-dioxides (4a-e) and 4-hydroxy-2-methyl-N-(pyridin-2-yl)-2H-1,2- benzothiazine-3-carboxamide 1,1-dioxide (PRX) into N-methyl saccharin (2) upon 254 nm irradiation in methanol or acetonitrile is reported. The structures of the products have been elucidated by spectroscopic methods and single crystal X-ray structure determination for 4a and 4d.
- Elghamry, Ibrahim,Doepp, Dietrich,Henkel, Gerald
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p. 849 - 852
(2008/04/12)
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- A simple and efficient synthesis of methyl 3,4-dihydro-2-methyl-2H-1,2- benzothiazine-3-carboxylate 1,1-dioxide from saccharin sodium salt
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A straightforward synthesis of methyl 3,4-dihydro-2-methyl-2H-1,2- benzothiazine-3-carboxylate 1,1-dioxide from saccharin sodium salt was achieved in five steps. Methyl 3,4-dihydro-2-methyl-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide found application as a precursor for the synthesis of a new class of quaternary ammonium derivatives that are potential antiosteoarthritis agents. Georg Thieme Verlag Stuttgart.
- Vidal, Aurelien,Madelmont, Jean-Claude,Mounetou, Emmanuelle
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p. 591 - 593
(2007/10/03)
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- Oxidative cyclization of N-alkyl-o-methyl-arenesulfonamides to biologically important saccharin derivatives
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Various biologically important saccharin skeletons and their N-alkyl derivatives have been efficiently prepared by chromium(VI) oxide catalyzed H5IO6 oxidation of N-alkyl-o-methyl-arenesulfonamides in acetonitrile. N-tert-Butyl saccharin skeletons were easily prepared by H5IO6-CrO3 oxidation of N-tert-butyl-o-methyl arenesulfonamides in the presence of acetic anhydride. The method that furnished the novel fluoro and trifluoromethyl substituted saccharin skeletons is characterized by two steps, a simple work-up procedure, a single purification and good overall yields from substituted toluene derivatives.
- Xu, Liang,Shu, Hong,Liu, Ying,Zhang, Suhong,Trudell, Mark L.
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p. 7902 - 7910
(2007/10/03)
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- Organic reactions in ionic liquids: N-alkylation of cyclic imides with alkyl halides promoted by potassium fluoride
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An ionic liquid based on 1-butyl-3-methylimidazolium hexafluorophosphate is used as an efficient reusable reaction medium in the N-alkylation of cyclic imides with alkyl halides promoted by fluoride ion.
- Hu, Yi,Chen, Zhen-Chu,Le, Zhang-Gao,Zheng, Qin-Guo
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p. 276 - 278
(2007/10/03)
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- 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
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Various N-alkylsaccharins were easily prepared in moderate to good yields by the reaction of N-alkyl(o- methyl)arenesulfonamides with (diacetoxyiodo)benzene in the presence of iodine under irradiation with a tungsten lamp (W-hv). On the other hand, irradiation of N- alky](omethyl)arenesulfonamide derivatives bearing various substituents on the aromatic ring with a high-pressure mercury lamp (Hg-hv), in the presence of (diacetoxyiodo)benzene and iodine gave the corresponding N-alkyl-1,2-benzisothiazoline-3- one-1-oxide derivatives in moderate yields, together with N- alkyl-1,2-benzisothiazoline-3-one-1,1-dioxide (saccharin) derivatives.
- Katohgi, Masashi,Togo, Hideo,Yamaguchi, Kentaro,Yokoyama, Masataka
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p. 14885 - 14900
(2007/10/03)
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- Ring contraction of 3-carboxamide or 3-carboxylate of 4-hydroxy-2- methyl-2H-1,2-benzothiazine-1,1-dioxide and analogous 1 (2H)-isoquinolinone- 3-carboxylate
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A novel ring transformation of 3-carboxylate or 3-carboxamide of 4- hydroxy-2-methyl-2H-1,2-benzothiazine-1,1-dioxide and analogous 1(2H)- isoquinolinone-3-carboxylate to the 5-membered rings upon the reaction with carbonyl compounds in the presence of primary or secondary amines is described.
- Khalaj, Ali,Adibpour, Neda
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p. 131 - 135
(2007/10/03)
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- Alkoxide-induced reactions of N-substituted saccharins. Synthesis of 1,2-benzothiazocine 1,1-dioxide and 2,3-dihydropyrrolo[1,2-b]-[1,2]benzisothiazole 5,5-dioxide derivatives
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The reactions of saccharin derivatives 1 with sodium alkoxides were studied. Under mild conditions, compounds 1a-f gave the corresponding open sulfonamides 5a-f. Under drastic conditions, β-(saccharin-2)propionic acid derivatives 1a,b reacted with sodium ethoxide affording saccharin and β-ethoxypropionic acid derivatives 4a,b. γ-(Saccharin-2)butyric acid derivatives 1c,d and γ-(saccharin-2)butyrophenone 1f reacted with sodium t-butoxide in dimethyl sulfoxide affording 5-substituted 6-hydroxy-3,4-dihydro-2H-1,2-benzothiazocine 1,1-dioxides 9. From mother liquors, 1-substituted 2,3-dihydropyrrolo[1,2-b][1,2]benzisothiazole 5,5-dioxides 10 were isolated several hours later, though not detected immediately after completing the reaction. When the reactions were carried out in t-butyl alcohol, the yields of 9 diminished and those of 10 increased with product ratio inversion. Different expermental observations on the possible pathway generating 9 and 10 are discussed.
- Blanco,Perillo,Schapira
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p. 145 - 154
(2007/10/02)
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- Retro-ene Reaction I: Reaction of N-Hydroxymethylsaccharin with Benzoyl Chlorides and Alkyl Halides
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N-Benzoylsaccharins, N-(saccharinylmethyl) benzoates and N-alkylsaccharins were synthesized from N-hydroxymethylsaccharin and the corresponding benzoyl chlorides or alkyl halides under different conditions.The reaction mechanisms are also discussed.
- Kim, Sung-Kyu,Moon, Jung-Gyen,Lee, Sang-Gyeong,Choi, Sam-Young,Cho, Su-Dong,et al.
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p. 353 - 356
(2007/10/02)
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- Novel Spirosuccinimides with Incorporated Isoindolone and Benzisothiazole 1,1-Dioxide Moieties as Aldose Reductase Inhibitors and Antihyperglycemic Agents
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Compounds from two novel series of spirosuccinimides were prepared.Analogs of series 2 possessed a spiro-fused isoindolone moiety while those of series 3 contained a spiro-fused benzisothiazole S,S-dioxide group.These compounds were evaluated as aldose reductase inhibitors (ARI) in vitro by their ability to inhibit glyceraldehyde reduction using a partially purified bovine lens aldose reductase preparation and in vivo as inhibitors of galactitol accumulation in the lens, sciatic nerve, and diaphragm of galactose-fed rats.Many members from the isoindolone series 2,particularly those containing an isoindolone N-methyl moiety, showed good in vitro and in vivo potency.The most potent member, the 6-chloro analog 32, was resolved, and aldose reductase activity was found to reside almost exclusively in the (+)-enantiomer.Compound 32 was approximately equipotent in the sciatic nerve of the galactose-fed rat to other cyclic imide ARI's of similar in vitro activity, namely sorbinil and ADN-138 and also to tolrestat, an acetic acid-based ARI (ED50's 4-8 mg/kg).Compounds from both series, 2 and 3, were also found to lower plasma glucose levels of genetically obese db/db and ob/ob mice with potency similar to that of ciglitazone.However, members from these series failed to lower insulin levels of the ob/ob mouse at the doses tested.
- Wrobel, Jay,Dietrich, Arlene,Woolson, Shiela A.,Millen, Jane,McCaleb, Michael,et al.
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p. 4613 - 4627
(2007/10/02)
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- N-ALKYLATION OF SULFONAMIDES USING ANION EXCHANGE RESIN
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Mono-N-alkylated sulfonamides were synthesized in high yields by reacting the sulfonamides supported on anion exchange resin with alkyl halides.
- Sanghavi, N.M.,Parab, V.L.,Patravale, B. S.,Patel, M. N.
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p. 1499 - 1504
(2007/10/02)
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- PHASE TRANSFER CATALYSED N-SUBSTITUTION OF 2H-1,2-BENZISOTHIAZOLIN-3-ONE 1,1-DIOXIDE
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The title compound on reaction with alkylating reagents and under the conditions of phase catalysis affords 2-substituted 2H-1,2-benzisothiazolin-3-one 1,1-dioxides (III).The conditions of the reaction and the mass spectra of the products are discussed.
- Svoboda, Jiri,Palecek, Jaroslav,Dedek, Vaclav
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p. 1304 - 1310
(2007/10/02)
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- N-Alkylation of Imides with O-Alkylisourea under Neutral Conditions
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N-Alkylation of imides with O-alkylisoureas has been found to accur under neutral conditions.Stereochemical data and structural factors indicate that an SN2 mechanism is operative.
- Inoue, Yoshio,Taguchi, Masaaki,Hashimoto, Harukichi
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p. 332 - 334
(2007/10/02)
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- INTRAMOLECULAR SULFONAMIDE-CARBOXAMIDE REARRANGEMENT.
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Several o-carboxy-N,N-dialkylbenzenesulfonamides rearrange intramolecularly to o-chlorosulfonyl-N,N-dialkylbenzamides upon treatment with an excess of thionyl chloride in an apolar solvent.
- Hovius, Klaas,Wagenaar, Anno,Engberts, Jan B. F. N.
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p. 3137 - 3140
(2007/10/02)
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