- Hydroxylamine as an oxygen nucleophile: Substitution of sulfonamide by a hydroxyl group in benzothiazole-2-sulfonamides
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Benzothiazole-2-sulfonamides react with an excess of hydroxylamine in aqueous solutions to form 2-hydroxybenzothiazole, sulfur dioxide, and the corresponding amine. Mechanistic studies that employ a combination of structure-reactivity relationships, oxygen labeling experiments, and (in)direct detection of intermediates and products reveal that the reaction proceeds via oxygen attack, and that oxygen incorporated in the 2-hydroxybenzothiazole product derives from hydroxylamine. The reaction, which is performed under mild conditions, can be used as a deprotection method for cleavage of benzothiazole-2-sulfonyl-protected amino acids.
- Kamps, Jos J. A. G.,Belle, Roman,Mecinovi?, Jasmin
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p. 1103 - 1108
(2013/03/28)
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- Synthesis of 2-Oxo and 2-Thioxo-3(2H)-benzothiazoleethanimic Acid Anhydride with Acetic Acid and Related Products
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The reaction of the appropriate 2-benzothiazolinone with 2-chloroacetamide under basic conditions afforded the 2-oxo-3(2H)-benzothiazolineacetamides 6-9.The 2-thioxo-3(2H)-benzothiazolineacetamide (10) was prepared by the reaction of 3-(carbethoxymethyl)benzothiazoline-2-thione with ammonium hydroxide.The reaction of acetamides 6-10 with the appropriate anhydride containing a catalytic amount of the sodium salt of the acid corresponding to the anhydride afforded the titled compounds 11-18 in excellent yields.The omission of the catalyst in the same reaction furnished a mixture containing 57percent of the titled compound, 37percent of the nitrile and 6percent of an unknown.Possible mechanism and supporting nmr, ir and mass spectral data are discussed.
- D'Amico, John J.,Bollinger, Frederic G.,Freeman, John J.
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p. 1503 - 1509
(2007/10/02)
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- Suppressing pain with benzothiazol-2(3H)-ones
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There are described pharmaceutical compositions containing as active substances benzothiazol-2(3H)-ones of the general formula STR1 wherein R represents a hydrogen atom or a methyl, methoxy, or ethoxy group. The pharmaceutical compositions serve as analgesics and antipyretics and possess little or no methemoglobin-forming activity.
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